How to Power a QT Py SAMD21 with Seeed's Lipo Rider Plus Board?

For Adafruit customers who seek help with microcontrollers

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
mmryspace
 
Posts: 13
Joined: Mon Aug 15, 2022 1:39 pm

How to Power a QT Py SAMD21 with Seeed's Lipo Rider Plus Board?

Post by mmryspace »

Hello everyone,

I am working on a project that I would like to have portable power using a rechargeable lipo and I am looking at Seeed's Lipo Rider Plus board (https://wiki.seeedstudio.com/Lipo-Rider-Plus/) which is a charging and boost board.

The lipo rider plus has a pin header and I am trying to understand what output(s) I use to power the QT Py.

I am unclear which of the header pin outputs to connect to the Vin pad on the bottom of the QT Py to supply USB power and Lipo Battery Power from the Lipo Rider Plus board.

Do I understand correctly that using the Vin and GND pads on the bottom of the QT Py is how I would connect an external power source if not plugging directly into the QT Py's USB-C port?

I also want to have an external on/off switch for the power between the Lipo Rider Plus board and the QT Py if possible. This is all new territory for me so any insights on how to proceed is greatly appreciated. Thank you.

Here is the header pin breakdown on the Lipo Rider Plus:

3V3 = 3V3 (250mA) OUT
EN = 5V (2.4A) Enable or Disable programmatically via micro controller I/O with priority over the onboard 5V ON/ OFF switch
GND
5V = 5V (2.4A) OUT (controlled by on/ off switch on the board)
GND
BAT = LIPO BATTERY OUTPUT
USB = 5V (2.4A) OUT (from USB-C charging input)

Image

User avatar
Franklin97355
 
Posts: 23912
Joined: Mon Apr 21, 2008 2:33 pm

Re: How to Power a QT Py SAMD21 with Seeed's Lipo Rider Plus Board?

Post by Franklin97355 »

You can connect the 5v to 5v gnd to gnd or use the 3v to 3v and gnd to gnd. It's probably good to disconnect it when you are powering the QTPY for programming.

User avatar
mmryspace
 
Posts: 13
Joined: Mon Aug 15, 2022 1:39 pm

Re: How to Power a QT Py SAMD21 with Seeed's Lipo Rider Plus Board?

Post by mmryspace »

Franklin97355 wrote: Thu Nov 03, 2022 1:02 pm You can connect the 5v to 5v gnd to gnd or use the 3v to 3v and gnd to gnd.
Thank you for the reply and to clarify: are you recommending that these header outputs and GNDs from the lipo board be connected directly to the QT Py 5V or 3V pins as well as GND and and not connect one of the header output pins to the 5V and GND pads on the bottom of the QT Py?

Is that because the lipo battery is connected to the lipo rider plus board and not directly to the QT Py board? My understanding was that the 5V and GND pads on bottom of the QT Py board were the best way to connect a lipo battery.

Also, I'll be needing the 5V and 3V pins on the QT Py for an OLED and a MIDI circuit.
It's probably good to disconnect it when you are powering the QTPY for programming.
I was hoping to implement an external hardware switch to turn the lipo board's power on and off and use the QT Py's on board USB-C for programming.

Thank you again for your help so far.

User avatar
michaelmeissner
 
Posts: 1821
Joined: Wed Aug 29, 2012 12:40 am

Re: How to Power a QT Py SAMD21 with Seeed's Lipo Rider Plus Board?

Post by michaelmeissner »

There are several ways to go forward. I do own the Lipo Rider Plus, and I've tried it out, but I haven't really used it in a project at this time.

An alternative is to use the QT PY BFF, which a board that is soldered underneath the QT PY, and it provides a JST plug for connecting lipo batteries. If the USB C connection is used, the BFF board will charge the battery. If it isn't used, the lipo battery will be used for power. There is a switch on the BFF that disconnects the battery (but not the USB C connection) that can act as a power on/off switch if you are running off of batteries. Now in terms of the BFF board, there are pluses and minuses compared to the lipo rider plus board:
  • The BFF board will charge batteries at 200mA. The documentation for the lipo rider plus says it can charge batteries up to 5 volts and 2 amps. So it is likely the Lipo rider plus will charge batteries faster than the BFF. But whether it will handle smaller batteries that want less charging power, I can't tell from the information.
  • The BFF board has a single LED to indicate the battery is charging.
  • The BFF board has a voltage divider on analog pin A2 that will allow you to monitor the battery power in the lipo battery or whether you are using USB. The Lipo Rider Plus does not provide information to the QT PY about power level, but it has 4 leds to allow you to see how full/empty the battery is visually.
  • The BFF board delivers power directly from the battery (i.e. 3.7 - 4.2 volts). The Lipo Rider Plus will convert the battery voltage to 5 volts. If you need 5 volts, then you would need to do the conversion. However, boosting the voltage to 5 volts will mean the battery won't last as long as it would with the BFF with the same battery.
  • Note the switch on the Lipo Rider Plus only covers the conversion to 5 volts. If you hook up pins to the raw battery power and/or 3.3v, the switch has no effect.
  • For me the biggest win for the Lipo Rider Plus is that I can charge the battery without disconnecting it from the JST and without powering the QT PY. With cosplay projects, I often want to take off the prop and charge it overnight without having the LEDs running like it would if I just plugged in the USB C connector to the QT PY.
  • Because it is made for the QT PY, the BFF will be a smaller package. Though with the 1200mAh and higher batteries that I use, I would be able to use velcro (tm) to attach the Lipo Rider Plus directly to the battery, and it wouldn't take up too much room.
  • On the other hand, having the BFF being soldered underneath the QT PY can be an issue if you want to attach the QT PY board to a small perma-proto board (like the small mint tin perma proto) or a small breadboard.
Now if you wanted to use the Lipo Rider Plus, the simplest way to get a small male USB A to male USB C cable, and plug in the A part into the Lipo Rider Plus and the C part into the QT PY. You use the switch on the Lipo Rider Plus to turn on/off the QT PY. You don't have to worry about interactions when programming the QT PY, since you would remove the USB cable in that case.

Instead, you could solder or connect the USB pin on the Lipo Rider Plus to the 5v pad underneath the QT PY and one of the ground pins to the ground pad next to it. On some of the QT PY's I believe there is a diode on these underneath pads that prevents them from supplying power if the USB cable is attached. I don't know if it would prevent USB current going to the Lipo Rider Plus.

User avatar
mmryspace
 
Posts: 13
Joined: Mon Aug 15, 2022 1:39 pm

Re: How to Power a QT Py SAMD21 with Seeed's Lipo Rider Plus Board?

Post by mmryspace »

michaelmeissner wrote: Thu Nov 03, 2022 2:18 pm There are several ways to go forward. I do own the Lipo Rider Plus, and I've tried it out, but I haven't really used it in a project at this time.

An alternative is to use the QT PY BFF, which a board that is soldered underneath the QT PY, and it provides a JST plug for connecting lipo batteries. If the USB C connection is used, the BFF board will charge the battery. If it isn't used, the lipo battery will be used for power. There is a switch on the BFF that disconnects the battery (but not the USB C connection) that can act as a power on/off switch if you are running off of batteries. Now in terms of the BFF board, there are pluses and minuses compared to the lipo rider plus board:
  • The BFF board will charge batteries at 200mA. The documentation for the lipo rider plus says it can charge batteries up to 5 volts and 2 amps. So it is likely the Lipo rider plus will charge batteries faster than the BFF. But whether it will handle smaller batteries that want less charging power, I can't tell from the information.
  • The BFF board has a single LED to indicate the battery is charging.
  • The BFF board has a voltage divider on analog pin A2 that will allow you to monitor the battery power in the lipo battery or whether you are using USB. The Lipo Rider Plus does not provide information to the QT PY about power level, but it has 4 leds to allow you to see how full/empty the battery is visually.
  • The BFF board delivers power directly from the battery (i.e. 3.7 - 4.2 volts). The Lipo Rider Plus will convert the battery voltage to 5 volts. If you need 5 volts, then you would need to do the conversion. However, boosting the voltage to 5 volts will mean the battery won't last as long as it would with the BFF with the same battery.
  • Note the switch on the Lipo Rider Plus only covers the conversion to 5 volts. If you hook up pins to the raw battery power and/or 3.3v, the switch has no effect.
  • For me the biggest win for the Lipo Rider Plus is that I can charge the battery without disconnecting it from the JST and without powering the QT PY. With cosplay projects, I often want to take off the prop and charge it overnight without having the LEDs running like it would if I just plugged in the USB C connector to the QT PY.
  • Because it is made for the QT PY, the BFF will be a smaller package. Though with the 1200mAh and higher batteries that I use, I would be able to use velcro (tm) to attach the Lipo Rider Plus directly to the battery, and it wouldn't take up too much room.
  • On the other hand, having the BFF being soldered underneath the QT PY can be an issue if you want to attach the QT PY board to a small perma-proto board (like the small mint tin perma proto) or a small breadboard.
Now if you wanted to use the Lipo Rider Plus, the simplest way to get a small male USB A to male USB C cable, and plug in the A part into the Lipo Rider Plus and the C part into the QT PY. You use the switch on the Lipo Rider Plus to turn on/off the QT PY. You don't have to worry about interactions when programming the QT PY, since you would remove the USB cable in that case.

Instead, you could solder or connect the USB pin on the Lipo Rider Plus to the 5v pad underneath the QT PY and one of the ground pins to the ground pad next to it. On some of the QT PY's I believe there is a diode on these underneath pads that prevents them from supplying power if the USB cable is attached. I don't know if it would prevent USB current going to the Lipo Rider Plus.
Thank you so much for this Michael, I really appreciate it. I initially wanted to use the BFF but opted for the Lipo Rider Plus for a lot of the reasons you've mentioned here. This pluses and minuses breakdown is super helpful!

I do want to connect solder or connect the USB pin on the Lipo Rider Plus to the 5v pad underneath the QT PY and one of the ground pins to the ground pad next to it. Would this mean I could use the USB-A output on the Lipo Rider plus in tandem. For example, the QT Py would be powered via the USB header pin as described and a peripheral device be plugged in?
On some of the QT PY's I believe there is a diode on these underneath pads that prevents them from supplying power if the USB cable is attached. I don't know if it would prevent USB current going to the Lipo Rider Plus.
Is the diode you are referencing mentioned here? https://learn.adafruit.com/adafruit-qt- ... ns-3073170

User avatar
michaelmeissner
 
Posts: 1821
Joined: Wed Aug 29, 2012 12:40 am

Re: How to Power a QT Py SAMD21 with Seeed's Lipo Rider Plus Board?

Post by michaelmeissner »

I don't know. Somebody who knows the QT boards better will have to comment....

Locked
Please be positive and constructive with your questions and comments.

Return to “Microcontrollers”