Serial / UART
The satlog.io Data Logger board has an isolated serial/UART interface accessible via a 4-pin JST PH 2.0 connector. The pinout is directly compatible with Victron equipment and cables (VE.Direct) but can also be used with generic serial/UART devices.
Interface
| Parameter | Value |
|---|---|
| Isolation | Galvanic |
| Signal level | 1.8 V, 3.3 V or 5 V, set by the connected equipment on pin 1 |
| Connector | 4-pin JST PH 2.0 |
| Format | 19200 baud, 8 data bits, no parity, 1 stop bit, no flow control |
| Direction | Receive only (RX) |
Pins are numbered left (4) to right (1).
| Pin # | Name | Description |
|---|---|---|
| 4 (Left) | Ground | Signal ground |
| 3 | TX | Serial TX (out) |
| 2 | RX | Serial RX (in) |
| 1 (Right) | Signal Level | UART Signal level (1.8V-5V) |
VE.Direct
SmartShunt and BMV battery monitors, MPPT solar chargers and Phoenix inverters are supported using any standard VE.Direct cable. The logger parses the VE.Direct text protocol (version 3.33):
- Every block is validated with the protocol checksum and invalid blocks are dropped.
- The parser resynchronises automatically after noise or a partial block.
- Fields reported as unavailable (
---) clear the stored value. - Values from consecutive blocks are merged, because devices send some fields at a lower rate.
The following fields are decoded.
| Group | Labels |
|---|---|
| Battery voltage | V, V2, V3, VS (starter), VM (mid-point), DM (mid-point deviation) |
| Battery current | I, I2, I3 |
| Power | P |
| State of charge, time to go, temperature | SOC, TTG, T |
| Consumed charge | CE |
| Panel (MPPT) | VPV, PPV, IL (load current), H19 to H23 (yield and maximum power) |
| Inverter AC output | AC_OUT_V, AC_OUT_I, AC_OUT_S |
| Inverter DC input | DC_IN_V, DC_IN_I, DC_IN_P |
| Battery history | H1 to H18 (depth of discharge, charge cycles, min/max voltage, alarm and discharge counters, energy totals) |
| Device state | ERR, CS, MODE, MON, MPPT, OR, AR, WARN, HSDS, Alarm, Relay, LOAD |
| Identification | PID, FW, FWE, SER# |
Decoded values are reported over Iridium at the report interval. Live readings are shown on the WiFi status page, and each valid block blinks LED2 blue.
Custom Equipment
Other serial equipment can be integrated by extending the logger firmware. The baud rate and framing are fixed for VE.Direct and configurable in custom firmware builds. Contact us with your protocol documentation for a quote.