I'm trying to make a Tamiya Blackfoot RC car run on a Raspberry Pi.
I've written a small C program for controlling the servo and the ESC/motor with a wireless gamepad. Everything is working fine when RasPi is getting its power from a separate power source (mains), but with the RC battery some problems occur.
When RasPi is connected to the RC battery (via 3A/5V UBEC) the servo control works but I have to be very careful when controlling the motor. If I accelerate too fast, at least one of the following will happen:
- WiFi dongle can't get enough power
- Joystick receiver can't get enough power
- Raspberry Pi reboots
I tried adding a 2200 μF electrolytic capacitor to prevent the brownouts, but it didn't seem to do the trick. I'm not (yet) very good with electronics so can you please tell me if there's anything to do to make the Raspberry car run without a second battery?
Here's a picture of the current setup. Please note that the voltage regulator is actually a 3A/5V UBEC, the resistors are 1 kΩ each, the cap is 2200 μF, and the motor controller is the closest to ESC (TEU-104BK) I could find.
Thank you for your attention. I feel so stupid.. I forgot the 7.2V connection from the battery to the ESC from the image. Updated the image.
- Input voltage: 6.6-7.2V
- Max. continuous current (FET spec): Forward 60A
- Operating range: 4.8~7.2 V
- Nominal voltage: 7.2 V
- Current no load: 2.4 A
- Current at maximum efficiency: 13.0 A
- Output at maximum efficiency: 63.2 W
- Current stall: 70.0 A
Servo (Tower Pro MG995)
- Operating voltage: 4.8~7.2 V
- Current Drain (4.8 V): 8.8 mA/idle and 350 mA no load operating
- Current Drain (6.0 V): 9.1 mA/idle and 450 mA no load operating
Battery (HPI Racing Plazma)
- Voltage: 7.2 V
- Capacity: 3300 mAh
- Cells: 6
- Brand new (I've got two of these)
Raspberry Pi GPIO
- Output voltage: 3.3 V
- Max current for pins 18 & 23: 16 mA each