imp004m Pin Mux

The imp004m is an integrated design which combines an imp module and WiFi antenna. In addition, the imp004m supports The imp004m is an integrated design which combines an imp module and WiFi antenna. In addition, the imp004m supports Bluetooth LE.

Pin Mux

Pin	uart BCAW	uart FGJH	uart HJ	uart Q	i2c NM	i2c QP	spi AHSR	spi GJKL	DFSDM	Analog In†	PWM	Pulse Count	Wake From Sleep	State Change Callback	PTPG Trigger
A	RTS						COPI			Yes	Yes				For Pin W
B	TX									Yes	Yes			Yes	For Pin C
C	RX									Yes				Yes
D										Yes	Yes			Yes
E														Yes
F		TX
G		RX						COPI
H		CTS	TX				CIPO							Yes
J		RTS	RX					CIPO				Yes
K								SCLK		Yes	Yes
L								CS*		Yes				Yes
M					SDA						Yes				For Pin N or P
N					SCL						Yes
P						SDA					Yes			Yes
Q				TX		SCL								Yes
R							NSS*		DATA					Yes
S							SCLK		CLK					Yes
W	CTS									Yes			Yes	Yes

* CS is driven by the controller in certain SPI modes (byte sync) and may be used to implement SPI peripheral functionality.

† The imp004m provides GPIO pins capable of supporting analog input. However, none of the module’s GPIO pins support imp API sampler operation.

CIPO was previously referred to as MISO. COPI was previously referred to as MOSI.

Notes

imp004m Identification

Call imp.info(). This returns a meta object with the property type, which is is a string containing the imp module name:

if (imp.info().type == "imp004m") {
    // Code running on imp004m...
}

Default Pin States

All of the imp004m’s pins are tri-stated (floating) by default, ie. on power on, after chip reset, or after deep sleep.

Analog IO, Sampler And Fixed-frequency DAC

The imp004m provides seven GPIO pins which are capable of being configured as analog signal inputs using pin.configure(). However, none of these pins — or indeed any of the imp004m’s GPIO pins — support an imp API sampler object. For audio input (a typical application of sampler), impOS supports DFSDM functionality (see below).

No imp004m pins support analog output. While the imp004m also lacks a true fixed-frequency DAC, it is nevertheless possible to use this API for audio output provided it is fitted with a simple filter circuit. For more details, please see the fixedfrequencydac.configure() documentation.

DFSDM

The imp004m incorporates STMicro’s Digital Filter for Sigma Delta Modulators (DFSDM) technology, which provides ADC functionality via an external analog unit by way of a high-speed dedicated serial bus on pins R (DATA) and S (CLK). This functionality is accessed through impOS’ dfsdm object.

For more information on DFSDM, please see this STMicro presentation.