Happy new year everyone,
I’ve been developing a board for DC sensing.
The particulars to this board are numerous! DC sensing, as I’ve learnt, is a complex subject with many safety related design elements.
With help from the Megni team and the community here I’ve developed a board with the following features, originally based on the emonTx v3.4 although now very different:
- DC sensing based on shunt monitor LMP8481, using external shunt up to 500A or internal shunt soldered across bridge on board.
- Bidirectional or unidirectional sensing with 2 shunt monitors for battery / generator application.
Bidirectionality set through software on ATMEGA328P, using PWM output of the ATMEGA.
ATMEGA328P processor, making use of four channels of its 10-bit ADCs.- replaced with external 12-bit ADC MCP3208 connected directly to ESP-12S
- ESP-12S wifi module.
- MicroSD card slot for storing data locally.
- Suitable for up to 60V DC systems. Onboard switching power supply based on TL2575-05, powered from <60V DC supply.
- Will come supplied with optically isolated FTDI adaptor for safe connection (galvanic isolation) to board while connected to solar or wind systems.
- Screw terminal connections for external shunts and ground.
- Voltage sensing
- In solar, can be used for up to 36V systems.
- Overvoltage protection.
- RFM69 radio.
This is a step in the direction of a charge controller for solar and wind.
I’ve left the RFM69 chip off the board due to the new wifi module being used. Please try change my mind on that if you think the RFM chip would be useful.
All here on github. https://github.com/danbates2/emonDC