In this lab exercise, you will create programs to implement 3 independent functionalities 1.using the ESP8266 NodeMCU and 2,3.using ARM mbed microcontroller

1.Assuming you have connected a LDR (light dependent resistor) to the analog input of a NodeMCU ESP8266 board (it has only one Analog input), write a program to display light readings on the Arduino Serial Monitor.

2.The SD Card uses a SDFileSystem library to use SD cards with the mbed microcontroller. Based on the memory management technique learnt in class and having imported the necessary files and libraries, and connected the SD card as suggested, write a program that writes a test text file to the card.

MicroSD Breakout	mbed Pin
CS	8 (DigitalOut)
DI	5 (SPI MOSI)
Vcc	40 (Vout)
SCK	7 (SPI SCLK)
GND	1 (GND)
DO	6 (SPI MISO)
CD	No connection

3. Using the mbed microcontroller, read the acceleration in three axes from the ADXL345 accelerometer and output the data to a host computer screen. Use the second SPI port (i.e. pins 11, 12 and 13) for connecting the accelerometer, applying connections shown in Tables below. Use either the ADXL345 (Analog Devices) data sheet at the link or the Table 2 below.

https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf (Page 23) (50 points)

The steps you should take while developing your code:

-set up the Master SPI port and call it acc

-set up USB link to the host computer

-declare a buffer to hold the data read from the accelerometers registers, two for each axis

-declare a data array with a int16_t specifier to hold the full accelerometer axis values, each combined from 2 bytes received from the registers

Table 1: ADXL345 Pin connections to mbed

ADXL345 signal name	mbed Pin
Vcc	Vout
Gnd	Gnd
SCL	13
MOSI	11
MISO	12
CS*	14

Table 2: Selected ADXL345 Registers

aAddress	Name	Description
0x00	DEVID	Device ID
0x1D	THRESH_TAP	Tap Threshold
0x1E/1F/20	OFSX, OFSY, OFSZ	X, Y, Z axis offsets
0x21	DUR	Tap duration
0x2D	POWER_CTL	Power saving features control. Devic epowers up in standby mode; setting bit 3 causes it to enter Measure mode.
0x31	DATA_FORMAT	Data format control Bits 7: force a self-test by setting to 1 6: 1=three-wire SPI mode; 0=four-wire SPI mode 5: 0 sets interrups active high, 1 sets them active low 4: always 0 3: 0=output is 10-bit always; 1=output depends on the range setting 2: 1=left justify result; 0=right justify result 1-0: 00= +/-2g; 01=+/-4g; 10=+/-8g; 11=_+/-2g
0x33:0x32	DATAX1:DATAX0	X Axis Data, formatted according to DATA_FORMAT, in 2s complement
0x35:0x34	DATAY1:DATAY0	Y Axis Data, as above
0x37:0x36	DATAZ1:DATAZ0	Z Axis Data, as above

^aIn any data transfer the register address is set first, and formed:

bit 7 = R/W* (1 for read, 0 for write); bit 6: 1 for multiple byte, 0 for single; bits 5-0: the lower 5 bits found in the Address column.