v4.0.0

Changes

• Use a TVS diode (SMAJ14) to protect the solar input from transients
• Reduce ISET a bit (to 800mA) to stay far away from the internal short circuit detection which samples the configuration resistor
• Properly sized voltage divider for the solar input
• Introduce a power switch to cycle the enter 3V0 if we get below 3.2V.
• Add proper C's to the Power Switch and Reset IC to avoid quick bouncing
• Non-functional PCB cleanups all over the place

v3.2.0

Warning

This fixes a critical bug coming from the Reset IC.

The problem comes from the activation chain: Reset IC ->

Full Changelog:

• c54b0b9 pcb, doc: clean up silk prints and push version number
• b4bd236 pcb, sch: replace LCSC ordering code for 3.0V LDO variant
• a9717ab pcb, sch: we are using +3V0 every so adjust all labels
• 4e75045 pcb, sch: add proper voltage divider (24V->2.4V) to ADC for VBUS
• 60c5f60 add floating kicad_pro file
• d75b03c pcb: improve vias below bq25185
• 61b36e6 pcb, sch: pull GPIO to high - otherwise uart bootloader might be unreliable
• 32e68b0 pcb, sch: add 10uF C to NRST so our reset delay moves from 50ms -> 0.4s
• 26c825a pcb, sch: increase RISET from 300Ohm to 360OOhm as it was too close to the short-detect fault detection threshold
• 776c66f pcb, sch: move nRST pull-up R10 from +3V3 to /VOUT

v3.1.0

• Use proper JLCPCB PCB template and fix all DRC errors/warnings
• Place zip tie hole for the battery in the mid of the battery

v3.0.2

• Convert to KiCad 10

• STAT is Open-Drain. So we need a resistor against 3V0 and no weirdo transistor stuff

v3.0.1

This release cleaned up the entire board design and increased user comfort.

• Added a switch for selecting application or bootloader

• Added Reset Button

• Option for manually forcing EN to VCC or GND using a jumper switch was removed. This is now controlled by the reset IC.

• Added a hole next to the battery so you can zip-tie the battery into its case. That's quite important if your setup is prone to falling.

• Reduced PCB size a bit to better fit into boxes

Warning

SDA/SCL of the connectors changed to untangle traces.

v2.0.1

Changelog

• Add C in front of Reset IC sensing line

Not optimal - but works for now. In the future I'll switch to a slower Reset IC but the required variant of the current one isn't available

v2.0.0

Changelog:

• Switched to semantic versioning

• Added a Reset IC that takes care of switching EN of the HT-CT62 if voltage before the 3.0v-LDO drops below 3.2v

Important

If you want to use the Reset IC: do not bridge the "EN" pin headers. The signal of this IC is "weak" - it can be overruled by a jumper without destroying the board.

V1.0

Only smaller changes:

• Replace LDO with 3V3 -> 3V0. We loose 1-2dBm of TX power but gain way longer run time. Also the native low voltage protection of Meshtastic will work now.

• Make silkscreen a bit bigger

v0.6

Bigger board changes this time:

• Lots of smaller non-functional changes reducing trace lengths to a minimum
• Replaced the CR123A battery with a classic 18650. The market of cheap CR123A 3.7V was just too small.
• Added a second I2C and also use proper Pull-Ups
• Using a thermistor with long legs instead of the SMD variant. This will be needed for temperature monitoring of unprotected LiPos
• Reduce jumpers to GPIO9 and ENABLE

Hopefully all bigger changes are done now - this one will be properly tested and then promoted to stable v1.0.0. Expect semantic versioning after this one.

v0.5

This fixes a thermal issue with the TI BQ25185:

Power supply tests showed that it's getting extremely hot when working with voltages >6V and a single Via below wasn't enough to get rid of the heat.