Microcontrollers

Atmel

ESP8266

Specs Description
Processor L106 32-bit RISC microprocessor core based on the Tensilica Xtensa Diamond Standard 106Micro running at 80 MHz
Memory 32 KiB instruction RAM 32 KiB instruction cache RAM 80 KiB user-data RAM 16 KiB ETS system-data RAM
External QSPI flash up to 16 MiB is supported (512 KiB to 4 MiB typically included)
IEEE 802.11 b/g/n Wi-Fi
Integrated TR switch, balun, LNA, power amplifier and matching network
WEP or WPA/WPA2 authentication, or open networks
GPIOs 16 pins
SPI
I²C (software implementation)
I²S interfaces with DMA (sharing pins with GPIO)
UART on dedicated pins, plus a transmit-only UART can be enabled on GPIO2
10-bit ADC (successive approximation ADC)

ESP32

Specs Description
CPU Xtensa LX6
#core 2
Architecture 32bit
CPU frequency 160MHz - 240MHz
Voltage 2v7 - 3v3
Connectivity Bluetooth (v4.2 BR/EDR and BLE), Wi-Fi (802.11 b/g/n)
RAM 520KiB
Flash ?
GPIOs 34 (10 capacitive sensing)
SPI 4
I2C 2
I2S 2
UART 3
CAN 1
ADC 12bit, 18 channels
DAC 8bit, 2 channels
PWM Motor and LED (up to 16 channels)
Crypto

RP2040

Specs Description
CPU Arm Cortex-M0+
#core 2
Architecture 32bit
CPU frequency 133Mhz
Voltage 2v7 - 3v3
Connectivity No
RAM 264KB
Flash 2MB
GPIOs 30
SPI 2
I2C 2
I2S 0
UART 2
CAN 0
ADC 12bit, 4 channels
DAC 0
Timers 3 16bit
PWM 16
USB 1.1 Host/Device

STM32F103C8T6

Reference manual | datasheet

There are a couple of boards with this microcontroller on it, mainly blue pill and black pill (note that their pinout differ)

Specs Description
CPU Arm Cortex-M3
#core 1
Architecture 32bit
CPU frequency 72Mhz
Voltage 2v7 - 3v3
Connectivity No
RAM 20KB
Flash 64KB
GPIOs 37
SPI 2
I2C 2
I2S 0
UART 3
CAN 1
ADC 12bit, 10 channels
DAC 0
Timers 3 16bit
PWM 1

$ dmesg -w
 ...
[591582.793849] usb 2-10: new full-speed USB device number 99 using xhci_hcd
[591582.943077] usb 2-10: New USB device found, idVendor=0483, idProduct=3748, bcdDevice= 1.00
[591582.943089] usb 2-10: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[591582.943094] usb 2-10: Product: STM32 STLink
[591582.943099] usb 2-10: Manufacturer: STMicroelectronics
[591582.943103] usb 2-10: SerialNumber: Qÿp\x06I\xc2\x86IQ1E\x17\xc2\x87
$ lsusb
 ...
Bus 002 Device 099: ID 0483:3748 STMicroelectronics ST-LINK/V2
 ...

There is Debian packages available to install dyrectly from github

$ st-info --version
v1.7.0
$ st-info --probe
Found 1 stlink programmers
  version:    V2J17S4
  serial:     51FF70064986495131451787
  flash:      65536 (pagesize: 1024)
  sram:       20480
  chipid:     0x0410
  descr:      F1xx Medium-density
$ st-util 
2021-04-28T18:20:32 WARN common.c: NRST is not connected
2021-04-28T18:20:32 INFO common.c: F1xx Medium-density: 20 KiB SRAM, 64 KiB flash in at least 1 KiB pages.
2021-04-28T18:20:32 INFO gdb-server.c: Listening at *:4242...
2021-04-28T18:20:34 WARN common.c: NRST is not connected
2021-04-28T18:20:34 INFO common.c: F1xx Medium-density: 20 KiB SRAM, 64 KiB flash in at least 1 KiB pages.
2021-04-28T18:20:34 INFO gdb-server.c: Found 6 hw breakpoint registers
2021-04-28T18:20:34 INFO gdb-server.c: GDB connected.
$ gdb-multiarch -n -q blink.elf
Reading symbols from blink.elf...
(gdb) target extended-remote :4242
Remote debugging using :4242
main () at blink.c:24
24              for (int i = 0; i < 500000; i++)
(gdb) load
Loading section .text, size 0x23c lma 0x8000000
Start address 0x080001b6, load size 572
Transfer rate: 3 KB/sec, 572 bytes/write.