SolarMeshtasticNode

# Evaluation SolarMeshtasticNode PCB v2.0.0

![Meshtastic Node](./pictures/MeshtasticNode_BQ25185_v200.jpg "The DUT")

## Setup

- Antenna: 5dBi omnidirectional, resonant on 868MHz
- Battery: KeePower, 4000mA, 3.7V, PartNo.  P1840C
- Solar: 9V, 400mA, Noname product from Aliexpress
- End of charge voltage: 4.2V
- Meshtastic Git Hash: f18a92e8c5be5a483a47b97adc58886808b12fc5 + Pin modifications 


LEDs S1/S2 and their transistors haven't been placed as I don't need them.

No sensors added.

# Meshtastic Configuration

- Role: CLIENT
- Power Saving: Disabled  (!)
- Telemetry rate: 1h

Other settings are default.

# Picture of the integrated PCB

![Meshtastic Node](./pictures/MeshtasticNode_BQ25185_v200_pcb.jpg "PCB in the box")


# Picture of the entire device

![Meshtastic Node](./pictures/MeshtasticNode_BQ25185_v200_device.jpg "Entire System")

# Power consumption (Grafana)

![Meshtastic Node](./pictures/MeshtasticNode_BQ25185_v200_voltage.png "Voltage Plot")

Analyzing the battery voltage and beacons during a low-sunlight scenario showed that there's a problem with the Reset IC: it's bouncing around the 3.2V.  As a fix  a 1uF capacitor was added directly next to the  sensing pin of the IC.

Testing continues.

# Lessons learned

Pretty mutch all construction things from the last tested version (v0.2) still apply and turned out be be very successful. Especially using the solar panel as sun shield with ~4mm plastic spacers keeps the system temperature low - even during the summer time.

Switching the battery type 18650 standard blocks was also a good decision. This reduced costs a lot and increased the overall storage capacity dramatically as they have trustable datasheets.