This blog post summarize interface ADC 0809 with 8051 using assembly programming
PS-TRAINER-8051 trainer kit is proposed to smooth the progress of learning and developing designs of MCU from Intel and NXP. It has the facility to connect PC’s 101/104 Keyboard, to enter user programs in Assembly languages. Serial communication achieved using 8051. It also supports C & assembly language in standalone kit (P89V51RD2). It’s designed as to facilitate On-board Programmer for NXP 8051 MCU through ISP on serial port.
ADC 0809
The ADC0808, ADC0809 data acquisition component is a Monolithic CMOS device with an 8-bit analog-to-digital converter, 8-channel multiplexer and microprocessor compatible control logic. The 8-bit A/D converter uses successive approximations the conversion technique. The converter features a high
Impedance chopper stabilized comparator, a 256R voltage divider with analog switch tree and a successive approximation register.
Interface ADC 0809 with 8051
8051 microcontroller it doesn’t have an On chip ADC to accept the digital input, it will not accept analog input, so we need a ADC to process the analog signal. For interfacing ADC 0809 we require 8 data lines. So ADC 0809 is an 8 bit ADC has 8 channels works on successive approximation conversion technique
Pin assignment with 8051
Circuit diagram to interface ADC 0809 with 8051
Assembly program to interface ADC 0809 with 8051
MEMORY ADDRESS | OPCODE | MNEMONICS |
8500 | 74 92 | MOV A,#98 |
8502 | 90 40 03 | MOV DPTR,#4003 |
8505 | F0 | MOVX @DPTR,A |
8506 | 90 40 01 | MOV DPTR,#4001 |
8509 | 74 01 | MOV A,#01 |
850B | F0 | MOVX @DPTR,A |
850C | 74 31 | MOV A,#31 |
850E | F0 | MOVX @DPTR,A |
850F | 74 01 | MOV A,#01 |
8511 | F0 | BACK: MOVX @DPTR,A |
8512 | 54 01 | ANL A,#01 |
8514 | 30 0A FA | JNB 0A,BACK |
8517 | 74 40 | MOV A,#40 |
8519 | F0 | MOVX @DPTR,A |
851A | 74 00 | MOV A,#00 |
851C | F0 | MOVX @DPTR,A |
851D | 90 40 00 | MOV DPTR,#4000 |
8520 | E0 | MOVX A,@DPTR |