Battery Power & Thunderborg
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Since switching from a picoborg rev my pi 3b won't boot from a fully charged battery pack (runs fine with mains power) Previously I had two battborgs one serving the rev and the other the pi 3b but connected to the same 9.6v battery ni-mh pack.
The pi is connected to the Thunderborg, an Ultraborg with 4 ultrasonic sensors, and has a Pan-Tilt hat with picamera v2 and two small servos and a neopixel led strip. The servos will rarely be used when the motors are running. Software wise the ultrasonic sensors are linked to a python/flask script which relays readings to an html/php front end. In turn this posts values to a python control script which interfaces with the Thunderborg.
I am assuming that the Thunderborg isn't passing sufficient current to fire the pi up and wonder whether powering the pi direct from the battery via a battborg and removing the power connections from the thunderborg to the pi might solve the problem. Or have I got something wrong?
piborg
Sat, 03/31/2018 - 11:41
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ThunderBorg power
The ThunderBorg is only capable of generating 1.5A for the 5V line, just like the BattBorg. Based on your list of parts I think you are right that it is not enough current to power everything at once.
Using a BattBorg to power the Raspberry Pi separately sounds like a good idea. You are correct that you will need to disconnect the 5V connections between the Raspberry Pi and the ThunderBorg to keep the power separated.
I would recommend having a single wire from any spare GND pin on the GPIO to the ThunderBorg GND connection on one of the 6-pin headers, this will make sure that both boards have the same level for 0V.
richard.jackson...
Sat, 03/31/2018 - 14:38
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ThunderBorg power
Thanks for the very quick reply. I'll re-jig the wiring as you suggest.
I guess an upgrade for the next generation/iteration is to up-rate the 5v line sufficient to run the latest and likely forthcoming generations of the Rpi
richard.jackson...
Tue, 04/03/2018 - 18:30
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Thunderborg Power
Sadly splitting the power and using a battborg to power the pi didn't work. Seems the 3b+ needs more current than it can deliver. I have invested in an adjustable dc:dc stepdown converter https://www.amazon.co.uk/dp/B015306ATQ?ref_=pe_3187911_248764861_302_E_D... which delivers up to 3amps. This works using the same approach as for the battborg so far. I chose this unit because of the led output voltage/current display. So far so good.