User's Manual

RN-42 Specification
Pin Name Description Default
1 GND
2 SPI MOSI Programming only No Connect
Input to RN42with weak pull
down
3 PIO6 Set BT master (HIGH=auto-master mode)
Set Baud rate (HIGH = force 9600, LOW = 115K
or firmware setting)
Input to RN42 with weak
pull down
4 PIO7
Input to RN42 with 1K pull
up
5 RESET Active LOW reset
6 SPI_CLK Programming only No Connect
7 PCM_CLK PCM interface No Connect
8 PCM_SYNC PCM interface No Connect
9 PCM_IN PCM interface No Connect
10 PCM_OUT PCM interface No Connect
11 VDD 3.3V regulated power input
12 GND
13 UART_RX UART receive Input Input to RN42
High level output from
RN42
14 UART_TX UART transmit output
UART RTS, goes HIGH to disable host
transmitter
15 UART_RTS Low level output from RN42
16 UART_CTS UART CTS, if set HIGH, disables transmitter Low level input to RN42
17 USB_D+ USB port Pull up 1.5K when active
18 USB_D- USB port
19 PIO2 Status, HIGH when connected, LOW otherwise Output from RN42
Input to RN42 with weak
pull down
20 PIO3 Auto discovery = HIGH
21 PIO5 Status, toggles based on state, LOW on connect Output from RN42
Input to RN42 with weak
pull down
22 PIO4 Set factory defaults
23 SPI_CSB Programming only No Connect
24 SPI_MISO Programming only No Connect
25 GND
26 NC RF pad keep all traces and planes clear.
27 GND
28 GND
29 GND
30 AIO0 Optional analog input Not Used
31 PIO8 Status (RF data rx/tx) Output from RN42
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