I had to make a new iteration of my alternative electronics hat for the Turtle Rover. On the former revision G I run into trouble with external I2C due to level shifting issues. Took the chance to simplify the circuit and route I2C and RS232 directly to the Raspberry Pi header instead through ARM micro-controller. So the server software can directly access any external peripherals through kernel drivers. Hardware description available on Github.
Turtle Rover hat rev. I top.
Turtle Rover hat rev. I bottom.
In addition I created a experimental motor driver board with dual ST L6206 DMOS full bridge driver as a direct drop-in replacement for the L298.
Experimental L6206 motor driver board as replacement for L298.
Inside of battery box with main battery and long range RC receiver.
Both, the BQ40Z80 battery management system and long range RC receiver are connected by I2C/SMB, routed to Turtle Rover electronics hat. That allows readout of all battery parameters as well as RC receiver parameters like link status, link quality, channel values etc. Hence a fully transparent and monitorable system. There is a provision for RS232 that may connect additional equipment inside the box to the electronic hat in the future (e.g. GPS).
Battery charger or external power socket on RH side.
The external charger or power socket has a direct battery management system connection. That allows an external power supply to charge the battery or power the entire Turtle Rover, e.g. from a solar panel or auxiliary battery. But external equipment (top mount) can also draw battery power for its own supply.
Top view of battery box mounted on rear bracket, holding the WLAN and long range RC antenna sockets.
Additional press nuts on the rovers rear bracket allowing easy installation of equipment on top and in combination with the main bracket fix points.
Pass-through of WLAN antenna cable into main electronics box. LH the battery harness.
WLAN antenna socket back side. Also shown the battery harness pass-through.
Rear bracket modified with additional press nuts and routing of WLAN antenna cable.
The WLAN cable uses a U.FL (IPEX) connector for a direct connection the modified Raspberry Pi 3 with external antenna socket. This way, no additional WLAN module is required.
Finally got my pledge for the Kickstarter Raspberry Pi Pi18650 dual battery hat that I supported.
Pi18650 Dual Battery Hat for Raspberry Pi.
The previous repair lasted for almost 9 month. Today the Power over Ethernet (PoE) hat from pi-supply.com that is powering my ADSB receiver died again when a thunderstorm was passing overhead. Like last time, no direct lightning but according to weather monitoring we got several >150kA flashes within 3km distance. As a result, again, the DC-DC converter Silvertel AG9805-M on PoE ceased to work. This time no short on the inputs, but no output voltage. Even having some more spares add hand I decided to replace this converter by a TDK CCG15-48-05S. This one has a higher input voltage tolerance, up to 75V and hopefully a better surge protection. Let’s see how long this last.