SHMod24

(Smart Home Module NRF24)

WORK IN PROGRESS.

This PCB is a universal microcontroller board with many optionally placable components. It aims to be an universal base-board for many projects especially around home automation.

Features

• Choice of ATMega328 (Arduino Pro Mini) or ESP8266 (ESP12-F) as the µC
• NRF24L01+ SMD with power filtering
• 6-30V input with buck converter
• Lithium battery support with charging and protection circuit
• 3.3V supply and logic
• Some MOSFET capable outputs
• RS485 Transceiver

Pinout

The pinout of the 28 pin header is listed here:

ESP8266	Arduino	Function	Pin	Pin	Function	Arduino	ESP8266
		GND	1	2	GND
		5V	3	4	VCC
		3.3V	5	6	3.3V
RX	RX	RX	7	8	TX	TX	TX
GPIO4	A4	SDA	9	10	SCL	A5	GPIO5
GPIO12	12	MISO	11	12	MOSI	11	GPIO13
GPIO15	8	CS	13	14	SCK	13	GPIO14
	A1		15	16	Analog in	A0	ADC (0-3.3V)
	A3		17	18		A2
		GND	19	20	GND
GPIO2	3	MOSFET	21	22		2	GPIO0
[GPIO13]* JP4	5	MOSFET	23	24		4
GPIO16	7	NRF_CE	25	26	MOSFET	6	[GPIO12]* JP5
	10	MOSFET	27	28	MOSFET	9

*) GPIO can be connected to this pin by bridging the mentioned jumper

ATTENTION: When the MAX3485 is mounted the Arduino doesn't want to be programmed most of the time. So make sure to pull pin P3 to 3.3V.

BOM

There are multiple different module groups that can be populated.

Information about what to watch out for for the different module groups will follow.

In the table is listed, which components to populate for a given module:

Module	Reference	Part
ESP8266	U1	ESP8266 12F
	R1, R2, R3, R11, R24	10k
ESP8266 ADC	R4	220k
	R5	100k
Arduino	IC1	Arduino Pro Mini
NRF radio	U2 or U7	NRF24L01+ SMD
	C11	100nF
	(C10)	10µF
3.3V regulator	U3	AP2112K
	C1, C2	1µF
Buck regulator	U6	LMR14010A or ACT4088 in deadbug style
	R9	LMR14010A: 56k ACT4088: 47k
	R10	10k
	C6	100n
	C7	LMR14010A: 2.2µF 50V ACT4088: 10µF 50V
	C8	22µF
	L1	LMR14010A: 22µH ACT4088: 4.7µH
	D1	Schottky 40V SMA
	(C9)	100µF
LiPo charger	U4	TP4056
	R6	2k2
	C5	100nF
	R14	1k
	D2	0805 SMD LED (charging indicator)
LiPo protection	U5	DW01A
	Q1	FS8205A
	R7	100
	R8	1k
	C3	100n
I²C pullup resistors	R12, R13	10k
RS485 Transceiver	U8	MAX3485

Project installation

• Make sure to run git clone with --recurse-submodules to include the necessary libraries too.
• To use the 3D Models, set the following environment variables:
  • ESPLIB : ${KIPRJMOD}\lib_includes\kicad-ESP8266
  • MYSLOCAL : ${KIPRJMOD}\lib_includes
  • Note: Sometimes you need to manually replace ${KIPRJMOD} with the absolute path to the project