Teensy 3.2 Arduino Shield + Lipo Battery

[vvishwa]

Hello Everyone,

I am currently using this shield from https://www.sparkfun.com/products/15716
and powering TEENSY 3.2 using external power. So far all good, however I also want to charge Lipo on this shield while external power is connected and switch to battery when needed. There is not much support on shield but I hope to get some help here.

Thanks
vvishwa

 

[kd5rxt-mark]

I would recommend that you take a look at the PowerBoost 500 Charger - Rechargeable 5V Lipo USB Boost @ 500mA+ from Adafruit, or if you need even more current capability, the PowerBoost 1000 Charger - Rechargeable 5V Lipo USB Boost @ 1A - 1000C. Each of these devices is made to take a connected 3.7V LiPo & boost it to 5VDC for powering devices typically powered from USB. Not only do they boost the LiPo battery levels to USB power levels, but they can also charge the LiPo while plugged in. Charging & switching between external USB power & battery power is all automatic. I use the PowerBoost 1000c in most of my Teensy products for convenient portability. In your project, you would then take the 5VDC output from the PowerBoost and connect it to the power input (barrel connector) on your SparkFun shield.

Hope that helps . . .

Mark J Culross
KD5RXT

 

[MichaelMeissner]

If you can live with 3.7-4.2 volt power when you are battery powered, some other alternatives include:

1) Use the Adafruit teensy featherwing adapter (https://www.adafruit.com/product/3200). If you use long male pins or stacking headers with long pins, you could solder the featherwing underneath the Teensy, and still plug it into the shield. The featherwing has a lipo plug. If you have power from USB or VIN, it will recharge the battery if needed. When the power goes away, it switches to being battery powered automatically. Note, it was designed for the 3.2. For the Teensy 4.0, there are a few adjustments you have to make. For the Teensy 3.5, 3.6, and 4.1, you have to mount the Teensy higher or mount the feather wing on top of the Teensy due to those boards being longer. Note, you don't have to cut the solder tab underneath the Teensy between VIN and VUSB.

2) Adafruit has 2 other boards that take power and a battery, and if the power is off, switch over to the battery: https://www.adafruit.com/product/5397 and https://www.adafruit.com/product/2124.

3) There used to be another solution from a Tindie seller that was made for the Teensy, but that product seems to be retired now.

 

[WMXZ]

I'm using https://www.adafruit.com/product/2124 and had no issues so far.
For this
- I cut VUSB/VIN on Teensy
- connect VUSB to 5V
- connect GND to GND
- connect VIN to VBAT
- I enable 500 mA loading current
I use an Adafruit 4400 mA Lipo battery

Teensy runs on Battery when loaded, after some time when needed Lipo loading kicks while Teensy continues to run.

 

[vvishwa]

If you can live with 3.7-4.2 volt power when you are battery powered, some other alternatives include:

1) Use the Adafruit teensy featherwing adapter (https://www.adafruit.com/product/3200). If you use long male pins or stacking headers with long pins, you could solder the featherwing underneath the Teensy, and still plug it into the shield. The featherwing has a lipo plug. If you have power from USB or VIN, it will recharge the battery if needed. When the power goes away, it switches to being battery powered automatically. Note, it was designed for the 3.2. For the Teensy 4.0, there are a few adjustments you have to make. For the Teensy 3.5, 3.6, and 4.1, you have to mount the Teensy higher or mount the feather wing on top of the Teensy due to those boards being longer. Note, you don't have to cut the solder tab underneath the Teensy between VIN and VUSB.

2) Adafruit has 2 other boards that take power and a battery, and if the power is off, switch over to the battery: https://www.adafruit.com/product/5397 and https://www.adafruit.com/product/2124.

3) There used to be another solution from a Tindie seller that was made for the Teensy, but that product seems to be retired now.

I am trying the featherwing adapter, I see LED solid yellow near J socket so I am assuming power is going LiPo. However even after couple hours of this state, unplugging USB doesn’t switch power. I am using Teensy3.2 and sample blink program works. So I am quite sure Teensy is working. Do u still need to cut between VUSB and VIN?

 

[MichaelMeissner]

I haven't had to cut the solder joint between VUSB and VIN.

 

[vvishwa]

I haven't had to cut the solder joint between VUSB and VIN.

I am using prop shield as well. Have all teensy pins connected to featherwing, everything related to teensy+propshield works. NixonMotion sketch gives calibration data which means prop is well connected. Do I have to use any jumper?

 

[MichaelMeissner]

In the past, I believe I've used that combination. I haven't used the prop shield in awhile but I never used the motion sensor, just the sound, flash memory, and neopixel/dotstar voltage level shifters.

As I understand it, the featherwing adapter has a MOSFIT or transistor on the VIN pin. If there is power on the VIN pin (i.e. typically from the USB cable if the solder pad has not been cut), then the featherwing will use that power to charge up the battery. If there is no power on the VIN pin, then the featherwing will route power from the battery to VIN.

I believe you don't have to actually connect the VUSB pin to the featherwing. Sometimes I would cut the solder pad, and install a switch between VUSB and VIN to turn off the Teensy. However, in doing so, it would not charge the battery.

I think I once cut the solder pad, and connected VIN and VUSB on the feather wing. I did not directly connect the VIN pin on the featherwing to the Teensy, but instead put a switch between featherwing VIN and Teensy VIN. This would allow the battery to recharge without power going to the Teensy (i.e. if I had a prop with flashing LEDs and a battery, I could recharge it overnight without removing the battery). I now prefer the Teensy 4.x method of having the Teensy power down if the ON/OFF pin is connected to ground for a period of time.

The prop shield doesn't have a pin for VUSB. I tend to use female stacking headers on the prop shield so it can be mounted above or below the Teensy. On the featherwing, I tend to use long male pins to connect both the Teensy and the featherwing as well as having pins to connect to the breadboard or stacking headers. On the outside pins for the featherwing, I use female headers so I can attach other feather wings.

This way I would put the prop or audio shields underneath the Teensy, connecting it to the breadboard. I would then insert the Teensy on top of it.

In a few Teensy 3.2's, I soldered a PCB that I ordered that fit between the Teensy and featherwing adapter to bring out the 10 pads underneath the Teensy.

Now with the Teensy 4.0, there are some modifications that you have to make if you use the featherwing (connecting 3.3v to AREF in the featherwing, not connecting the on/off pin to the audio output, and not using analog audio output, not connecting the A10/A11 pins since the Teensy 4.0 doesn't have A10/A11 in those positions).

 

[vvishwa]

In the past, I believe I've used that combination. I haven't used the prop shield in awhile but I never used the motion sensor, just the sound, flash memory, and neopixel/dotstar voltage level shifters.

As I understand it, the featherwing adapter has a MOSFIT or transistor on the VIN pin. If there is power on the VIN pin (i.e. typically from the USB cable if the solder pad has not been cut), then the featherwing will use that power to charge up the battery. If there is no power on the VIN pin, then the featherwing will route power from the battery to VIN.

I believe you don't have to actually connect the VUSB pin to the featherwing. Sometimes I would cut the solder pad, and install a switch between VUSB and VIN to turn off the Teensy. However, in doing so, it would not charge the battery.

I think I once cut the solder pad, and connected VIN and VUSB on the feather wing. I did not directly connect the VIN pin on the featherwing to the Teensy, but instead put a switch between featherwing VIN and Teensy VIN. This would allow the battery to recharge without power going to the Teensy (i.e. if I had a prop with flashing LEDs and a battery, I could recharge it overnight without removing the battery). I now prefer the Teensy 4.x method of having the Teensy power down if the ON/OFF pin is connected to ground for a period of time.

The prop shield doesn't have a pin for VUSB. I tend to use female stacking headers on the prop shield so it can be mounted above or below the Teensy. On the featherwing, I tend to use long male pins to connect both the Teensy and the featherwing as well as having pins to connect to the breadboard or stacking headers. On the outside pins for the featherwing, I use female headers so I can attach other feather wings.

This way I would put the prop or audio shields underneath the Teensy, connecting it to the breadboard. I would then insert the Teensy on top of it.

In a few Teensy 3.2's, I soldered a PCB that I ordered that fit between the Teensy and featherwing adapter to bring out the 10 pads underneath the Teensy.

Now with the Teensy 4.0, there are some modifications that you have to make if you use the featherwing (connecting 3.3v to AREF in the featherwing, not connecting the on/off pin to the audio output, and not using analog audio output, not connecting the A10/A11 pins since the Teensy 4.0 doesn't have A10/A11 in those positions).

Thanks for detailed explanation. I am using feather adapter, can’t see a pin for VCC. I see that in teensy, but do not want to use as that will defeat whole purpose. I have ordered new lipo just to isolate issue.