Pi UpTime - portable Pi platform.
Pi UpTime provides GPIO connections, analog ports, UPS, RTC & battery power enabling Raspberry Pi to be mobile.
Pi UpTime - portable Pi platform.
Pi UpTime provides GPIO connections, analog ports, UPS, RTC & battery power enabling Raspberry Pi to be mobile.
Pi UpTime (a two board combination) enhances the capabilities of the Raspberry Pi, making it mobile by providing a power source.
(Note - when we refer to a Raspberry Pi - we refer to both the Pi and the Pi+.)
Typical Pi UpTime applications include:
Data Logging and remote Data Loggers - enhances capabilities of the Raspberry Pi for data logging applications and for remote data loggers.
Security and Surveillance - ensures that the security and surveillance applications you create have the necessary power and as well as an accurate time stamp.
Mobility - the compact, rechargeable power source makes the Pi mobile. Many applications such as a digital cameras, game controllers, portable oscilloscopes, mobile phones, drones and more are made possible using the Pi UpTime.
What else can you use Pi UpTime for? Raspberry Pi has created an amazing ecosystem. It is refreshing to see many different applications users are creating; how students use the Raspberry Pi to enhance programming skills, and how the Raspberry Pi is used for a variety of low cost computing needs. We believe that using Pi UpTime boards, many Raspberry Pi applications will be created more quickly and easily.
Pi UpTime board-1 connects all GPIOs to the Raspberry Pi with an easy-to-connect terminal block. Power and Ground connections are also available via the terminal block. Convenient solder points on Pi UpTime board-1 enable pull-up or pull-down resistors to be connected to the GPIO pins. (These resistors are usually needed with sensors.) Details on board-1 are covered in the FAQ below (FAQ #33).
Pi UpTime board-2 provides power for up-to 17 hours of run time on a Raspberry Pi, making the Raspberry Pi mobile. The batteries are rechargeable. The power to the Raspberry Pi is regulated - providing stable power, even when the sensors and other peripherals attached to the Raspberry Pi demand more power. This prevents brown-outs and unnecessary reboots of the Raspberry Pi. Software monitors the battery charge level, and can shut down the Raspberry Pi automatically when the battery power level runs too low when there is no external power.
Pi UpTime includes a very accurate Real Time Clock (RTC) temperature compensated and accurate to <5 seconds a month. This enables time-critical security, surveillance and data logging applications where an accurate event time stamp is needed.
In addition, Pi UpTime adds two analog input ports to complement the GPIO capabilities. Using these analog ports, it is easy to add sensors for voltage, current, stress, strain and many other sensor signals.
Finally Pi UpTime includes a reset switch which can restart the Raspberry Pi. A red LED flashes to indicate a Pi reset and restart.
Pi UpTime facilitates your Raspberry Pi application:
Mobile Applications: Need to take the Raspberry Pi with you? Are you creating an application using the Raspberry Pi which requires it to be mobile? Need to use the Raspberry Pi as a mobile phone, or for robotics or drones, or as a mobile computer or ....? Need to connect sensors to the Raspberry Pi? Pi UpTime enables mobility for the Raspberry Pi.
The common question asked about a mobile Raspberry Pi is how do we charge the batteries and keep them charged? There are many methods for doing that. One obvious method is to use a mobile solar panel. The pictures below show a mobile solar panel which was purchased from eBay, rated for 5V-7W. Such solar panels are commonly used for charging cell phones. These solar panel can be used with the Raspberry Pi or for charging Pi UpTime batteries.
Data Logging Applications: Pi UpTime allows sensors - analog or digital - to be easily used for data input. The accurate RTC time stamp can be logged with the data collected and viewed using the Raspberry Pi.
Security and Surveillance Applications: A camera or a motion sensor or both when connected to the Raspberry Pi, can provide a robust security and surveillance solution. Even when external power fails, with Pi UpTime, your security and surveillance applications continue to operate normally.
Before Pi UpTime, your GPIO connections may have looked something like this:
Have you ever feared accidentally disconnecting one of these connections? Have you ever faced removing one of the pins and wondering which pin it goes to after it is unplugged? Streamline your data connections with Pi UpTime. Make the connections secure. Document your connections ( preferably via a picture using QLite Pro).
An application example using the Pi UpTime board-1 with one temperature sensor is shown below.
Besides securing your GPIO connections, Pi UpTime:
1) Provides two analog ports to collect data from analog sensors such as voltage sensors, current sensors, stress / strain sensors and more - complementing the GPIO capability on the Raspberry Pi.
2) Very accurate, Real Time Clock (RTC), temperature compensated to make sure the Raspberry Pi has the correct time, on or off the network.
3) Provides steady power to the Raspberry Pi - protects the Raspberry Pi from brown-outs preventing unwanted downtime. Pi UpTime accepts power input from an external source and charges its batteries at the same time it powers the Raspberry Pi.
4) Battery Backup power and UPS - continuous operations of Pi plus Pi UpTime for up-to 17 hours when batteries are fully charged. It takes about 6 hours to fully charge the batteries.
5) Power Reset switch on board-2 allows a restart of the Raspberry Pi. With Pi UpTime, there is no need to plug or unplug the external power source to reset the Pi. A Power-Reset switch on Pi UpTime resets the Pi after a shutdown. A red LED flashes to signal the Pi reset.
6) Software provided with Pi UpTime monitors the battery charge level, includes sample code for using the analog ports and includes instructions for setting up the RTC. The software can be downloaded from the web at initial Pi UpTime setup. (With the "Pragmatic" ordering option, you get it ready to use!)
II. ADDITIONAL FEATURES
1. Industry Standard Batteries - uses standard 18650 protected rechargeable batteries instead of custom batteries. Replacement batteries are widely available.
2. Clips secure the battery cells. 18650 battery clips holds the batteries in place. No Velcro or glue is needed.
3. Documented pins - no need to refer to GPIO reference charts and diagrams.
4. Terminal Blocks provide mechanical stability for wiring connections to your sensors. These connections cannot be disconnected accidentally.
5. Solder points for easy addition of pull-up or pull-down resistors, commonly needed for sensor signals.
6. Mounting holes and standoff's provide mechanical stability of the Raspberry Pi and the Pi UpTime assembly.
7. Power and Ground connections. Ample terminal-block ports and solder points for 5V, 3.3V and Ground. Prevents connection congestion.
8. Fuse and Power Protection. A temperature sensitive and current sensitive fuse protects exposed 5V and Ground ports on the terminal block. The battery charging chip also monitors the battery temperature and shuts the charging off if the batteries get too hot.
9. Works with all current models of the Raspberry Pi. See special ordering instructions in the FAQ for Pi UpTime versions usable with older versions Raspberry Pi (Models A and B.)
10. Uses the I2C bus - allows other peripherals to work with your application. The I2C bus on the Pi is shared with other I2C peripherals. Pi UpTime documentation lists the I2C address used by the ADC chip and the RTC chip.
11. On-board LED's shows the status of Pi UpTime. A red LED indicates a reboot and glows when the Power Reset switch is pressed. See our FAQ for more information on other LED's.
III. Pledges At A Glance
All pledges get our Thank You email and updates on our progress.
Benevolent - a pledge of $1 or more to help us along.
Evangelist - A pledge of $12 (or more) gets you the Evangelist Reward. You will get a Pi UpTime board-1 with the necessary standoffs.
Evangelist Bundle- A pledge of $24 (or more) gets you Evangelist bundle. You will get two Pi UpTime board-1's with the necessary standoffs.
Believer - A pledge of $49 (or more) gets you Believer Reward. You will get a Pi UpTime board-2, two batteries with the necessary standoffs.
Techie's Delight - A pledge of $59 (or more) gets you Techie's Delight Reward. You will get a Pi UpTime with both the boards, two 18650 rechargeable batteries and the necessary standoffs.
Pragmatic - A pledge of $150 (or more) gets you Pragmatic Reward. A ready-to-go unit which includes a Pi UpTime along with a Raspberry Pi 2, a SD card, latest Raspbian-OS, updates to the Raspbian-OS, the necessary monitoring software, and a temperature and humidity sensor (uses 1 GPIO). Start monitoring the temperature and humidity wherever you want. You can also easily add other sensors to it. We will also be glad to send this as a gift to a designated person. Please let us know via email, or when you make the pledge, in the comments section as to who the gift is designated for.
STEM accelerator - We will build 10 of the Pragmatic-reward units and will provide 4 hours of hands-on training for a class of up to 10 students. Hands on training in the classroom are restricted to the Bay Area. Training for other locations will be delivered via a conference call or video call.
The training is our way of saying Thank You. They will be learning from the experts.
Once we are ready with the units, the school will receive 10 Raspberry Pi 2 units fully assembled with a Pi UpTime. The Pi 2 will be ready-to-go; loaded with the latest Raspbian-OS, software for monitoring temperature and humidity. The assembled unit uses 1 GPIO and includes one temperature and humidity sensor.
IV. Stretch Goals
We have several enhancements planned to our road map. We hope we can reach the Stretch Goals as well.
Stretch Goal 1.
Mobile data logger - On reaching $30,000 funding, we will fund documentation and How-To guides for creating a mobile data logger which can be leveraged for other uses as well. We will start with a simple data logger to log temperature and relative humidity. Topics covered will include:
1) Setup of the Pi UpTime.
2) Log data - specifically temperature and humidity data with time stamps.
3) Save the data on a Google drive of your choice - this allows access to the data from anywhere.
4) Use web services to monitor data (e.g. RPI-monitor)
5) Show how the application can be extended for other sensors
6) Recommend some solar panels so you can charge a mobile data logger in the field.
This guide will be available to everyone who has made a pledge.
Stretch Goal 2.
Chassis for all - On reaching funding of $80,000+, we will design a chassis which will fit a Raspberry Pi+ with Pi UpTime boards and batteries. This chassis will allow your Pi to be tucked away neatly on a desktop or similar indoor environment.
Stretch Goal 3.
Extend Pi UpTime - On reaching funding of $100,000+ we will undertake the design of a daughter card with two additional batteries. We want to conquer the 24 hour operating time barrier - more than one day of uninterrupted running - without external power. A daughter card with two additional batteries would easily extend the run time to beyond 24 hours.
Beyond Stretch Goal 3.
Beyond $150,000 - We need to climb new mountains!!! We want to add a Graphics Interface to show the battery level, trigger a text message when the battery runs low etc. We would love to hear from you as to what would you want - software, more sensors, more How-To projects...
V. Pi Models Supported
All Pi models are supported by Pi UpTime.
By default, we ship the larger, 40 pin connector which works with the Raspberry Pi+ (models A+, B+, 2). If you need to use your Pi UpTime for older models of the Pi, please indicate that in the comment section of your pledge.
Mounting holes on Pi UpTime align with the mounting holes on the Pi. Using a board standoff, both board-1 and board-2 can be mounted securely on the Pi.
And for the newly introduced Raspberry Pi models.
Pi UpTime is designed to be the last board on the Raspberry Pi stack i.e. the top side of the Pi UpTime board-2 does not have connector pins for attaching another board. All the boards delivered for the Kickstarter pledges will be such a board.
When we reach our goal on Kickstarter we will trigger the project to make the final modifications needed to complete both the boards for production. We will be able to complete manufacturing, testing and shipping within ninety days.
All the prototypes have been tested to minimize the risk associated with the development. The manufacturers of the prototype boards are ready to initiate production and have made suggestions on what we can do to meet Kickstarter production.
VII. Frequently Asked Questions (FAQ)
1. Can I charge my phone or other USB device from the Pi UpTime batteries? Yes – the Raspberry Pi has USB ports which provide power and using these USB ports, it is possible to charge a USB device or a phone. Please keep in mind that the run time will be reduced. Note – not all devices can be charged from the USB ports on the Raspberry Pi. The current (amps) provided by the Raspberry Pi may not be sufficient to charge some devices. For example, some models of the iPad require a high charging current (2.1A). When an iPad is plugged into the USB port, it does not charge.
2. Will the Raspberry Pi work as the batteries recharge? The electronics on board simultaneously powers the Raspberry Pi system and charges the Pi UpTime batteries. If there are no batteries installed in the battery clips, only power to the Raspberry Pi is provided. The Raspberry Pi system has priority over the battery charge current – so your Pi system will always operate as designed.
3. If the external power fails, will the USB devices connected to the USB ports on the Pi continue to receive power from the Pi UpTime batteries? Yes – the power is available to the Raspberry Pi board. For example, if you have a cellular modem adapter on the Raspberry Pi, it will continue to operate as long as the battery has the necessary power. When the battery runs low, with no external power, the shutdown sequence is triggered.
4. Will the Pi UpTime boards work with other boards? Yes, as long as the other boards follow the Raspberry Pi Foundation standards for connections.
5. Do you plan to add relays or other additions to the Pi Uptime boards? If you have thoughts or ideas on how to enhance the boards or make them more useful, please send us an email. We would like to listen to what you have to say.
6. What is the warranty on the board and what does it cover? Warranty is for 90 days and covers all parts and repair labor. If there are any issues, mail the board back to us with the purchase receipt or a copy of the receipt. We will mail you a replacement.
7. Where can I get additional standoff's (spacers) for the boards? Many sites sell those. An example of such a site is the Adafruit website and the recommended standoff is the Brass M2.5 Standoffs for Pi available here (11mm).
8. Can I use the Raspberry Pi power micro-USB port to charge the batteries and to power the Pi? No, you have to use the micro-USB port on the Pi UpTime board. If the existing Pi power port (micro-USB port on the Raspberry Pi) is used, the Pi will power up, the Pi UpTime batteries will not re-charge the batteries after a discharge cycle.
9. Do you plan to sell the Pi-UpTime board-2 with only one battery instead of two? No – not at this time. If there is a demand for a single cell board – we will consider it. Please let us know if you would like a board with a single cell and other functions e.g. an 8 channel A-D converter. Also let us know what other functionality you would like to see added to this board.
10. Will the Pi UpTime work with only one battery? Yes, the available operating time will be reduced approximately by half. The electronics on board are flexible enough to charge one or two 18650 batteries.
11. How is the shutdown sequence triggered? Python code is provided to monitor this. This code is usually run as a "cron" job. Documentation is provided to show how this can be setup to monitor the system automatically.
In the code, there are two defined values: (1) lowValert - the low Voltage alert value. When the Voltage falls below this value, an alert is sent. (2)lowVshut - the Voltage at which the shutdown sequence is triggered. In the Python code provided, when the battery voltage reaches approximately 3V (lowValert), the low battery warning is triggered to all logged in users using the "wall" command. When the battery voltage reaches 2.9V (lowVshut), the automated shutdown process is triggered. The unit shuts down in about two minutes once the alert is seen. All of the above parameters can be reprogrammed using the program sources provided.
12. Why is a Real Time Clock (RTC) needed? The Raspberry Pi does not have an on-board clock. It depends on the Internet and time synchronization services available in the OS. The Raspberry Pi uses time services on the Internet to synchronize its clock. If the internet is not available, the time will drift. If the Raspberry Pi is used for applications where time is critical, it is important to have a RTC.
13. Are all RTC’s similar? No, cheaper versions of the RTC drift a lot i.e. lose the time accuracy quickly. Low drift RTC chips maintain the clock time very accurately – typically a few seconds drift per month. Pi UpTime uses a chip with a temperature compensated crystal and a high accuracy RTC.
14. If I do not need the RTC, can I get a board-2 without the RTC? No, not at this time. We would love your feedback as to whether we should eliminate the RTC function from the board.
15. Can I get just a RTC board for the Raspberry Pi? Yes – there are many RTC boards available for the Pi. The cost will vary depending on the accuracy of the clock. An example of such a board is available from Adafruit, Pi Store as well as from other suppliers.
16. Does a Raspberry Pi need a Power Reset Switch? When the Pi is shutdown (using the shutdown command), the easiest way to reboot the Pi is to unplug and plug the micro USB power connector. With the Pi UpTime board connected, there is power available to the Raspberry Pi from the Pi UpTime batteries. Without a Power Reset switch, one way to reboot the Pi is to disconnect the power as well as the batteries. To prevent this tedious sequence, a Reset Switch is provided on Pi UpTime board-2. The Reset Switch disconnects the power source (as long as the switch is pressed) and then makes the power available to the Pi, triggering the reboot sequence and lighting the LED reset indicator.
17. Does the Reset Switch affect the RTC? No – the RTC continues to get power from the batteries when the Reset Switch is used to power up the Raspberry Pi. RTC accuracy is not affected.
18. How long can the RTC operate with the Pi shutdown? For a few years. The RTC consumes a fractional micro amp to keep its functions active. At that power consumption, the clock should last for a long-long time. In our labs we are still awaiting that event. It could be a few years. Calculations show that once the shutdown sequence is triggered, the RTC could be active for at least five years with fully charged batteries.
19. What batteries are included with Pi UpTime? We include two 18650 rechargeable batteries. These batteries are rated for 2600 mAh by the manufacturer. The batteries also include a protective circuit from the manufacturer which protects the batteries from under-voltage and over-voltage.
20. How long will it take to charge the PI UpTime battery? It depends on how much the battery has been discharged. A fully discharged 18650 battery (with the discharged cell voltage around 3V or more) should charge to full capacity in approximately 6 hours (at approximately 1.2 Amps.)
21. Can I use unprotected 18650 cells? Not recommended as the cells could be discharged significantly, damaging the battery. This deep-discharge reduces the life of the cell. Pi UpTime board shuts down when the battery voltage reaches appx. 2.8V. Pi will shut down as well as there will be no more power converted from the battery by Pi UpTime.
22. Why is battery protection needed? Some USB devices connected to the Raspberry Pi may continue to drain the power even after the system is shut down. This could drop the voltage of the battery below safe levels. If the battery voltage drops below 2.8V Pi UpTime does not convert the power form the batteries any more. Only when the external power is available, will the Raspberry Pi reboot and the Pi UpTime batteries start charging.
23. What is the rating for the terminal block connectors used with board-1? The terminal block connections are spaced 3.5mm apart suited for 16-28 AWG wire. The Voltage rating is for the terminal block is 150 V and the current rating is 6 Amps. Housing material for the terminal block is Polyamide (PA), Nylon and the operating temperature is -30°C to 105°C. Screws used are M2 and the torque needed is 0.4 Nm (3.5 Lb-In).
24. Do you plan to add 5V to 3.3V buffer chips so that the GPIO pins only see 3.3 V? Currently we do not. The connector block on the Raspberry Pi for GPIO access does not protect the pins and yet, people use the Pi responsibly. Also, our experience shows that the buffer chips over long periods of use could add uncertainty as to how the GPIOs behave. We believe all Raspberry Pi users are responsible individuals who will use the Raspberry Pi and the GPIO responsibly.
25. Do you plan to create an enclosure for the Raspberry Pi and the Pi UpTime stack? One of the stretch goals of this Kickstarter is to create such a chassis.
26. Can we replace the 18650 batteries with higher capacity units? Yes. We assume that the people doing this are responsible and can do that independently.
Also note that higher capacity batteries will take longer to charge. They will also increase the run time.
27. Can we replace the batteries when the battery life is over? Yes. This was one of the key factors for choosing the 18650 batteries - batteries with high power capacity and batteries which are widely available. We want to make sure you can use Pi UpTime for a long, long time.
28. What method is used for charging the batteries? The electronics use the "Constant Current followed by Constant Voltage" (CCCV) method for charging the 18650 batteries. There is a lot of literature available on the web for the CCCV charging methods and why this method is critical for batteries.
29. Are there LED’s on the Pi UpTime board? Yes – there are four LED’s on board. The red LED comes on when the power Reset Switch is pressed and is used to indicate a power reboot sequence. Three other LED's indicate the operational status of the board. See table below.
The important thing to note is that when there is no external power, none of the LED's are lit. If all three LED's are lit - something is wrong. Most likely there are no batteries installed or the batteries are installed incorrectly.
30. Do you have battery polarity protection on Pi UpTime? Yes. There is a reverse voltage sense electronics built into Pi UpTime which will not power Pi UpTime or the Raspberry Pi if the batteries are not installed correctly. Note - even if one battery is installed correctly - the unit functions well.
31. Which RTC chip do you use? We use the NXP PCF2129 RTC chip with an internal temperature compensated oscillator. The chip can do a lot more. Let us know if you plan to use the chip for other purposes such as alarms etc. Please refer to the NXP web site for additional details on this chip.
32. Which ADC chip do you use? We use the Microchip MCP3428 four channel ADC chip. The first two channels are used to check the input voltage and the battery voltage. The other two channels are available for your use via the terminal block provided. Please refer to the Microchip web site for more details on this chip.
33. Can you share details on board-1? Yes. The images for the prototype board-1 has been shown in a number of places. For example, look at Evangelist Reward described above.
One of the goals for the kickstarter is to modify the design of board-1 based on the feedback received. Here are some of the changes we are incorporating:
- All solder point are 2.54 mm (1 mil) apart. You can solder standard headers in these solder points.
- A central 3.3V power rail has been created (shown by red bus below).
- A central ground rail has been created (shown by green bus below).
- All GPIO's are connected to the terminal blocks - each GPIO groups are shown separately. The GPIO connections match the GPIO layout on the Raspberry Pi.
- All GPIO numbers (G followed by number) and Raspberry Pi pin numbers (P followed by a number) are silk-screened on the board. No need to refer to the Raspberry Pi documentation.
With the spacing being standard, you can solder either male or female headers. The image below shows board-1 with female headers available at Adafruit and at MCM Electronics. These headers are the same headers used on Arduino boards. (Note: the pin-outs are not compatible with Arduino, but are compatible with Raspberry Pi.) You can also solder on male headers.
VIII. USE OF FUNDS
The funds will be used for finishing the testing and modifications associated with the prototypes and for the manufacturing of the Pi UpTime boards. When we exceed the first target and meet our stretch goals, we will use the additional funds to complete the additional projects as discussed in the stretch goals.
IX. ABOUT THE TEAM
We have a GREAT team working on the Pi UpTime. Key people who have contributed to the Pi UpTime project include:
Shethal Thomas - our very capable design engineer with a can-do attitude. She 'can-did' the mechanical designs in CAD for the boards and how they connect together. She loves football (soccer) and also actively participates at her church helping the community she lives in and schools nearby.
Hank Semenec - our trusted adviser - a reliable Senior Electrical Engineer and a longtime friend. Hank reviewed the development work, made suggestions and improvements and also helped doing amazing soldering feats with the prototypes to make the boards work!!!
Alan Chan - a versatile geek who specializes in IT, computers, network design and operations as well as network security. He and also dabbles with photography. Alan has been instrumental in creating some of the video segments. He has used Open Source tools to eliminate the background noise from the audio.
Percy Kawas - founder and CEO of Alchemy Power Inc. - a company focused on creating power from renewable sources. In creating solutions to measure how the Alchemy Power Inc. systems performed, he created the PiUpTime boards. Besides dabbling with Raspberry Pi and renewable sources of power, he loves football (soccer), hockey (field hockey), chickens, carpentry and hiking.
X. ABOUT ALCHEMY POWER INC.
Alchemy Power Inc. is a Silicon Valley startup founded by seasoned technology pioneers whose mission is to create power from renewable sources. Using patented technology, Alchemy Power Inc. plans to introduce products leveraging wind energy to create power - especially when traditional wind turbines sit idle.
Risks and challenges
The biggest risk for the product is component availability and manufacturing of the product. Manufacturing of this board is dependent on the semiconductor suppliers (supply chain). It is possible that the availability of the components could adversely affect the supply and availability of the boards. We are working with leading global manufacturing companies in the heart of Silicon Valley to minimize this risk.
Li-Ion 18650 rechargeable batteries vary in consistency and quality from manufacturer to manufacturer. Manufacturing consistency of the 18650 batteries across different production runs may also impact the quality of the 18650 batteries. We have narrowed down to one supplier who follows world class manufacturing guide lines on reliable, consistent manufacturing. Once funded, we will be designating alternate suppliers to minimize our risks.
While the above may indicate some risks, we have tried to use commonly available parts. We have talked to our manufacturer and we are ready to assemble and ship the rewards in a timely manner.Learn about accountability on Kickstarter
- (35 days)