Open Island

  https://item.taobao.com/item.htm?_u=7boo1l33af8&id=42935368105&spm=a1z09.2.0.0.7fde2e8dj6p3hs 全新力做,5A降压恒压恒流模块,带MPPT功能，用太阳能电池板给电池充电可提升充电电流一倍以上，有效缩短充电时间，减小太阳能电池板体积。可为蓄电池、锂电池等充电，带转灯控制，方便观察充电状态。可配多功能电压表，输入电压、输出电压、输出电流、输出功率都可以直观显示，完全可脱离万用表使用。可做为大功率LED驱动模块。  如需防反灌 理想二极管请点以下链接：    8A   http://item.taobao.com/item.htm?id=42364220733  15A  http://item.taobao.com/item.htm?id=42364220733 操作说明： 模块本身已带散热片，加大加粗大磁环电感温升更小，高频长寿命电解电容。 MPPT效果实测双比： 测试条件：18V/50W单晶太阳能板，7.4V/5AH锂电池，12月早晨10点左右在阳台。太阳不大，晒在身上暧暧的，防盗窗挡住了部分太阳。 MPPT不起作用时的充电电流0.896A， （光线比较强，相机快门比较快，表头上数字在拍照片时显示会不全，懂点摄影的朋友应该都明白。) MPPT值调至太阳能板最大功率点时的充电电流1.651A，提升近一倍的充电电流，效果相当明显。     需要外壳请点以下接：  http://item.taobao.com/item.htm?id=13621241047

Of course there are cheap chinese BMS, I have few, some are not even working on cutting off voltage.  And I don't think cutting off should be job of BMS, a good BMS should : monitor voltage with out dran out current with divide resistor not bound to chemistry, could be Lipo, Life..etc monitor temperature of each cell or connection able to communicate wire or wireless Better to be sleep   https://www.instructables.com/Arduino-LTC6804-Battery-Management-System/ Base on LTC6804, SPI interface. The BMS is configured for a battery pack are composed of A123 LiFePO4 cylindrical batteries in 12S8P configuration. The A123 cells have the following characteristics: LTC6804 can monitor upto 12 cells, wih arduino lib https://github.com/dcaditz/BMS_V4 and could be available as PCB from tao Another good code, with presentation on 6804 https://github.com/ayushagrawal/BMS-Arduino not sure what is the difference on 6802-1, it works also on 12 cells. 6802-2 could be addressed  There is a newer versio

 TTGO lora32 is a esp32 with lora chip, with various version... it was very confusing when they keep on pushing new version but with no clear documentation. different version may have different connection pin on lora chip, and others. and the version is not marked on PCB.  same thing on their git pages. upto 2021/11 I found 2: https://github.com/LilyGO https://github.com/Xinyuan-LilyGo the second one seems to be more upto date. For example you can find a version identification on there: https://github.com/Xinyuan-LilyGO/LilyGo-LoRa-Series Still very confused, at the end I found that mines are V2 TTgo also make some examples for connecting to TTN, but lack of clear notes, it make me very difficult to read and use. here seems to be the one with TTN V3 https://github.com/Xinyuan-LilyGO/LilyGo-LoRa-Series/blob/master/docs/en/LilyGo_LoRa_Series_Quick_Start_On_TTN.md There are listed in git: https://awesomeopensource.com/projects/lmic/lorawan https://www.thethingsnetwork.org/forum/t/lmic-nod

 It's possible to config client with attached sensor, in 2.4 version, there is IIC ones, maybe we can also use serial  function for sensors as well.( Serial Module Configuration ) Currently Supported Sensor Types ​ 2.4 Sensor I 2 C Address Data Points BMP085 0x76, 0x77 Temperature and barometric pressure BMP180 0x76, 0x77 Temperature and barometric pressure BMP280 0x76, 0x77 Temperature and barometric pressure BME280 0x76, 0x77 Temperature, barometric pressure and humidity BME680 0x76, 0x77 Temperature, barometric pressure, humidity and air resistance MCP9808 0x18 Temperature INA260 0x40, 0x41, 0x43 Current and Voltage INA219 0x40, 0x41, 0x43 Current and Voltage INA3221 0x42 3-channel Current and Voltage LPS22 0x5D, 0x5C Barometric pressure SHTC3 0x70 Temperature and humidity SHT31 0x44 Temperature and humidity PMSA003I 0x12 Concentration units by size and particle counts by size PMSA003I 0x12 Concentration units by size and particle counts by size DFROBOT_LARK 0x42 Temperature, ba

I still have some ttgo lora V2.0 on hand. Base on the web info of meshtastic,  https://meshtastic.org/docs/hardware/devices/lora/?t-lora=v2.0#resources-2  this board has charger IC problem(I knew it). and for ready made firmware selection, try T-loraV2.1-1.6 I tried to flash with 2.4 and 2.3015 firmware, it took a while, but it was able to load the firmware. with android app, I can connect to each device through BT, first you need to config the region, then, the device will reboot. connect through BT, the messaging between 2 devices, works fine.  But on the other hand, I also have some heltec cube cell, which is a cypress CPU with newer lora chip. it only has 16MB memory, far from enough for meshtastic. The OLED has serveral pages,  For the Lora V2.1-1.6 and V2.1-1.8, Shorting IO12 to ground will progress through the screen pages and/or wake up the device. A simple push switch can be added for this purpose. https://meshtastic.org/docs/hardware/devices/lora/gpio/

 The original wire of soco TC  from battery connector to controller is very thin, and very long. with original set up I got about 2400W But inside the battery pack it use XT60 and 10 AWG wire, which seems more reasonable for a 40A load. wire near the air breaker. the contact does not seem good enough for me. Battery connector side. some one says the connect is heated in long drive. This is the connector from motor, there are hall sensors and  Also a motor temp NTC sensor(the white wire) which did not connected. I change the connector and the wire from battery XT60 to ESC, in basic, since the battery pack inside use 10 awg and xt60, it should be good. but for future changes I use a XT90 and bigger wire. with same battery package, I got a slightly better result. 2665W   From previous search in 02, I knew the ESC can take higher voltage, but it would go into protection at 75V. Original battery pack voltage. Adding one cell in serial So, I added a lipo cell at external, and test the perfor