Heltec ESP32+OLED+Lora, hardware testing

you can easily find some good boards from china, but most of them lack of accurate document...
Hrere is an example;

https://hackaday.io/project/26991-esp32-board-wifi-lora-32

the board looks good with lora and a 128x64 OLED, but the IIC and reset connection is important, since pin can be muxing easily, so every board could be different.

pinMode(16,OUTPUT); 
digitalWrite(16, LOW); // set GPIO16 low to reset OLED 
delay(50); 
digitalWrite(16, HIGH); // while OLED is running, must set GPIO16 to high 

and, if needed, edit your Wire.begin() to Wire.begin(4,15); (4 = SDA 15 SCL) 

i tested it with the Adafruit SSD1306 and the Acrobotics SSD1306 Librarys 
both work. 

Display size is 128x64

There are discussions on these boards on TＴＮ as a LORA node..or maybee single ch gateway?

Heltec has a git : https://github.com/Heltec-Aaron-Lee

And there is another copy call TTGO
https://de.aliexpress.com/item/TTGO-LORA32-868-915-Mhz-SX1276-ESP32-Oled-display-Bluetooth-WIFI-Lora/32840222847.html

Compare to the board I was using from wemos, heltec  seems to have a better pin out...

Topic		WEMOS OLED with GPS	Heltec OLED+Lora
Link		https://github.com/Ldsrc2008/AIS-encode-arduino
# PINS		18
Pin Label Top		X
Pin Label Bottom
EN Button		X
BOOT Button		X
Battery
Breadboard friendly
Battery Mgmt
GPIO00	bootmode	X	X
GPIO01	TXD0 touch1	X	X
GPIO02	GPIO2 must also be either left unconnected/floating, or driven Low, in order to enter the serial bootloader	X
GPIO03	RXD0	X	X
GPIO04	IIC SCL, touch0	IIC SCL OLED	OLED_SDA
GPIO05	IIC SDA	IIC SDA OLED	LORA_SCK
GPIO06	SCK/CLK*	X
GPIO07	SDO/SD0*	X
GPIO08	SDI/SD1*	X
GPIO09	SHD/SD2*
GPIO10	SWP/SD3*
GPIO11	SCS/CMD*	X
GPIO12	Internal flash stuff, touch5	X	X
GPIO13		RX1	X
GPIO14	touch6		LORA_RST
GPIO15	boot message,touch3		OLED_SCL
GPIO16		TX1	OLED_RST
GPIO17			X
GPIO18			LORA_CS
GPIO19			LORA_MISO
GPIO21			X
GPIO22			X
GPIO23			X
GPIO25		Rx2	X
GPIO26		TX2	LORA_IRQ
GPIO27	touch7		LORA_MOSI
GPIO32	touch9		X
GPIO33	touch8		X
GPIO34			X
GPIO35			X
GPIO36	SENSOR_VP	X	X
GPIO37			X
GPIO38			X
GPIO39	SENSOR_VN	X	X
3.3v		2
5v		2
Vin/Vcc
GND		3
RST
EN
BATT
NC

The goods are finally here, I was thinking they were using module, but Heltec mount all the chips on one PCB....For cost down I guess....

 the little copper coil is for wifi or BT...
There is a PCB printed antenna on board, but they did not use it...
maybe there is some thing wrong with the PCB antenna

 there is a battery connector on it, need to find out if there is a charging IC??

you can see the lora chip is under the OLED










I read a test from here:

it leads to here https://www.alictronix.com/archives/860

the code use SSD1306 lib, but the code is on the web page, you need to check the "", since my arduino did not accept the word type, so need to change it. and you also need to have arduino lora lib.
 #include “SSD1306.h”<===check this and all other serial print...

there is another example:
https://robotzero.one/heltec-wifi-lora-32/
this one using u8x8 lib for OLED.....which I did not use...
but robotzone has more clear note on the code and pin out...


https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic/10247/40


this post give me a lot of information:
such as this board use MCP73831 lipo charger, and the battery connector is a micro JST 1.25mm.



For the internal connection with lora chip, according to this:

// GPIO5 -- SX1278's SCK // GPIO19 -- SX1278's MISO // GPIO27 -- SX1278's MOSI // GPIO18 -- SX1278's CS // GPIO14 -- SX1278's RESET // GPIO26 -- SX1278's IRQ(Interrupt Request) #define SS 18 #define RST 14 #define DI0 26


To get TTN work on this board:

 https://github.com/matthijskooijman/arduino-lmic
discussion:
https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic/10247/31

Single Channel Gateway part 2

it's actually using https://github.com/kersing/ESP-1ch-Gateway-v5.0 for ESP32 and 8266, but when compiling I got an error on wpa.h....no idea where should I find it.....