Created
August 7, 2021 04:35
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eeprom programmer
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| #define SHIFT_DATA 13 | |
| #define SHIFT_CLK 3 | |
| #define SHIFT_LATCH 4 | |
| #define EEPROM_D0 5 | |
| #define EEPROM_D7 12 | |
| #define WRITE_EN 2 | |
| void setAddress(int address, bool outputEnable) { | |
| // Send address (and output-enable bit) to shift registers. | |
| shiftOut(SHIFT_DATA, SHIFT_CLK, MSBFIRST, (address >> 8) | (outputEnable ? 0x00 : 0x80)); | |
| shiftOut(SHIFT_DATA, SHIFT_CLK, MSBFIRST, address); | |
| // Store the address in the shift register's output latch | |
| digitalWrite(SHIFT_LATCH, LOW); | |
| digitalWrite(SHIFT_LATCH, HIGH); | |
| digitalWrite(SHIFT_LATCH, LOW); | |
| } | |
| byte readEEPROM(int address) { | |
| // Setup data pins to read input. | |
| for (int pin = EEPROM_D0; pin <= EEPROM_D7; pin += 1) { | |
| pinMode(pin, INPUT); | |
| } | |
| setAddress(address, true); | |
| // Construct a byte from the 8 data pins. | |
| byte data = 0; | |
| for (int pin = EEPROM_D7; pin >= EEPROM_D0; pin -= 1) { | |
| data = (data << 1) + digitalRead(pin); | |
| } | |
| return data; | |
| } | |
| void writeEEPROM(int address, byte data) { | |
| // Setup data pins to write output. | |
| for (int pin = EEPROM_D0; pin <= EEPROM_D7; pin += 1) { | |
| pinMode(pin, OUTPUT); | |
| } | |
| setAddress(address, false); | |
| // Set each of the 8 pins according to the bit position for the given data. | |
| for (int pin = EEPROM_D0; pin <= EEPROM_D7; pin += 1) { | |
| digitalWrite(pin, data & 1); | |
| data = data >> 1; | |
| } | |
| // Address setup time. | |
| delay(10); | |
| // Trigger write operation. | |
| digitalWrite(WRITE_EN, LOW); | |
| // WRITE_EN is wired to a R/C circuit | |
| // low pulse duration is ~700ns | |
| digitalWrite(WRITE_EN, HIGH); | |
| // Allow the EEPROM write cycle to complete | |
| delay(10); | |
| } | |
| void printContents() { | |
| /* Print the first 255 bytes of data from the EEPROM */ | |
| for (int base = 0; base <= 255 /* 512*1024 */; base += 16) { | |
| byte data[16]; | |
| for (int offset = 0; offset <= 15; offset += 1) { | |
| data[offset] = readEEPROM(base + offset); | |
| } | |
| char buf[80]; | |
| sprintf(buf, | |
| "%03x: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x", base, | |
| data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7], | |
| data[8], data[9], data[10], data[11], data[12], data[13], data[14], data[15]); | |
| Serial.println(buf); | |
| } | |
| } | |
| void disableDataProtection() { | |
| // aa -> 5555 | |
| // 55 -> 2aaa | |
| // 80 -> 5555 | |
| // aa -> 5555 | |
| // 55 -> 2aaa | |
| // 20 -> 5555 | |
| writeEEPROM(0x5555, 0xaa); | |
| writeEEPROM(0x2aaa, 0x55); | |
| writeEEPROM(0x5555, 0x80); | |
| writeEEPROM(0x5555, 0xaa); | |
| writeEEPROM(0x2aaa, 0x55); | |
| writeEEPROM(0x5555, 0x20); | |
| } | |
| void setup() { | |
| Serial.begin(115200); | |
| Serial.println("Starting up..."); | |
| pinMode(SHIFT_DATA, OUTPUT); | |
| pinMode(SHIFT_CLK, OUTPUT); | |
| pinMode(SHIFT_LATCH, OUTPUT); | |
| digitalWrite(WRITE_EN, HIGH); | |
| pinMode(WRITE_EN, OUTPUT); | |
| /* Allow 5 seconds to set trigger on scope */ | |
| delay(5000); | |
| disableDataProtection(); | |
| writeEEPROM(0, 0xFF); | |
| delay(10); | |
| printContents(); | |
| Serial.println("All done."); | |
| } | |
| void loop() { | |
| } |
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