RadioHAT

Raspberry Pi PCIe HAT for radio modules

This HAT is an all-in-one radio modules development platform with the following features.

• Built-in logic analyzer - All pins routed to the transceivers (SPI and various GPIO signals) are also routed to additional Raspberry Pi GPIO pins, to allow the RPi to monitor and record the state of communication pins. See the pinalyzer repository for details.
• Adjustable linear voltage regulator - To supply power-intensive transceivers, there is a dedicated LDO regulator with adjustable output. The output voltage is adjustable between 2.9 and 3.6 V.
• Power consumption measurement - There is a built-in INA219 current monitor which allows to measure the power consumption of the transceiver. See the dc-powermon repository for details.

While these features are useful, they are entirely optional. Without them, the HAT is a simple adapter board for mini-PCIe cards (half-size or full-size) and can be left with most of the components unpopulated, except for the RPi pin header, PCIe connector and the card latch.

RadioHAT

Card for modules from Dorji

Card for modules from GNice-RF

Card for modules from Ebyte

Card for Wio-E5

Mini PCIe connector pinout

Different vendors (RAK Wireless, Waveshare, SeeedStudio and others) offer radio modules in the mini-PCIe card form factor. However, there seems to be no consensus on any specific pinout. Naturally, RadioLib defines its own version to add to the confusion. However, we try to adhere to the standard Mini PCIe 2.0 pinout in the following ways:

• Mini PCIe 2.0 SMB pins are used for I2C
• Mini PCIe 2.0 USB pins are used for USB
• IRQs, resets and various GPIOs are connected to Mini PCIe 2.0 digital signals
• 3.3V voltage pins are used for most modules, though sometimes 5V is optionally used

The complete pinout of the connector (and therefore the PCIe cards) is shown below.

Pin	Signal	Signal	Pin
1	GPIO0	3V3	2
3	IRQ0	GND	4
5	IRQ1	5V	6
7	GPIO1	NC	8
9	GND	NC	10
11	RST0	NC	12
13	RST1	NC	14
15	GND	NC	16
17	NC	GND	18
19	NC	NSS1	20
21	GND	NC	22
23	NC	3V3	24
25	NC	GND	26
27	GND	5V	28
29	GND	I2C_SCL	30
31	PPS	I2C_SDA	32
33	NC	GND	34
35	GND	USB_D-	36
37	GND	USB_D+	38
39	3V3	GND	40
41	3V3	LED0	42
43	GND	LED1	44
45	SPI_SCK	LED2	46
47	SPI_MISO	5V	48
49	SPI_MOSI	GND	50
51	NSS0	3V3	52

Raspberry Pi pinout

The shield routes the Mini PCIe connector signals to the following Raspberry Pi GPIO header pins. The pins with prefix SNS_ are connected to the digital signals through a series resistor and GPIO, allowing to use the RPi as a makeshift logic analyzer.

Pin	Signal	Signal	Pin
1	3V3	5V	2
3	I2C_SCL	5V	4
5	I2C_SDA	GND	6
7	SNS_NSS0	SNS_SDA	8
9	GND	SNS_SCL	10
11	SNS_SCK	RST0	12
13	SNS_MISO	GND	14
15	SNS_MOSI	GPIO1	16
17	3V3	IRQ1	18
19	SPI_MOSI	GND	20
21	SPI_MISO	RST1	22
23	SPI_SCK	NSS0	24
25	GND	NSS1	26
27	NC	NC	28
29	SNS_IRQ0	GND	30
31	SNS_RST0	SNS_GPIO0	32
33	SNS_NSS1	GND	34
35	SNS_IRQ1	IRQ0	36
37	SNS_GPIO1	GPIO0	38
39	GND	SNS_RST1	40