board: support for NRF51 HW-651 (#4712)

NRF51: Support for NRF51 HW-651 board
* smoketest
* removed redundant flash-method
* smoketest fix
* description and links
* link fix

GNUmakefile

@@ -867,6 +867,10 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=elecrow-rp2350      examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=hw-651              examples/machinetest
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=hw-651-s110v8       examples/machinetest
+	@$(MD5SUM) test.hex	
 ifneq ($(WASM), 0)
 	$(TINYGO) build -size short -o wasm.wasm -target=wasm               examples/wasm/export
 	$(TINYGO) build -size short -o wasm.wasm -target=wasm               examples/wasm/main

src/machine/board_hw-651.go

@@ -0,0 +1,77 @@
+//go:build hw_651
+
+package machine
+
+// No-name brand board based on the nRF51822 chip with low frequency crystal on board.
+// Pinout (reverse engineered from the board) can be found here:
+// https://aviatorahmet.blogspot.com/2020/12/pinout-of-nrf51822-board.html
+// https://cr0wg4n.medium.com/pinout-nrf51822-board-hw-651-78da2eda8894
+
+const HasLowFrequencyCrystal = true
+
+var DefaultUART = UART0
+
+// GPIO pins on header J1
+const (
+	J1_01 = P0_21
+	J1_03 = P0_23
+	J1_04 = P0_22
+	J1_05 = P0_25
+	J1_06 = P0_24
+	J1_09 = P0_29
+	J1_10 = P0_28
+	J1_11 = P0_30
+	J1_13 = P0_00
+	J1_15 = P0_02
+	J1_17 = P0_04
+	J1_16 = P0_01
+	J1_18 = P0_03
+)
+
+// GPIO pins on header J2
+const (
+	J2_01 = P0_20
+	J2_03 = P0_18
+	J2_04 = P0_19
+	J2_07 = P0_16
+	J2_08 = P0_15
+	J2_09 = P0_14
+	J2_10 = P0_13
+	J2_11 = P0_12
+	J2_12 = P0_11
+	J2_13 = P0_10
+	J2_14 = P0_09
+	J2_15 = P0_08
+	J2_16 = P0_07
+	J2_17 = P0_06
+	J2_18 = P0_05
+)
+
+// UART pins
+const (
+	UART_TX_PIN = P0_24 // J1_06 on the board
+	UART_RX_PIN = P0_25 // J1_05 on the board
+)
+
+// ADC pins
+const (
+	ADC0 = P0_03 // J1_18 on the board
+	ADC1 = P0_02 // J1_15 on the board
+	ADC2 = P0_01 // J1_16 on the board
+	ADC3 = P0_04 // J1_17 on the board
+	ADC4 = P0_05 // J2_18 on the board
+	ADC5 = P0_06 // J2_17 on the board
+)
+
+// I2C pins
+const (
+	SDA_PIN = P0_30 // J1_11 on the board
+	SCL_PIN = P0_00 // J1_13 on the board
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = P0_23 // J1_03 on the board
+	SPI0_SDO_PIN = P0_21 // J1_01 on the board
+	SPI0_SDI_PIN = P0_22 // J1_04 on the board
+)

targets/hw-651-s110v8.json

@@ -0,0 +1,3 @@
+{
+	"inherits": ["hw-651", "nrf51-s110v8"]
+}

targets/hw-651.json

@@ -0,0 +1,7 @@
+{
+	"inherits": ["nrf51"],
+	"build-tags": ["hw_651"],
+	"serial": "uart",
+	"flash-method": "openocd",
+	"openocd-interface": "cmsis-dap"
+}