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projects:esp [2015/02/04 20:30] – [PCF8591] darron | projects:esp [2017/01/12 22:44] (current) – external edit 127.0.0.1 | ||
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The three devices are a Microchip MCP23016 digital I/O expander, NXP PCF8591 ADC/DAC and Microchip 24LC512 EEPROM. | The three devices are a Microchip MCP23016 digital I/O expander, NXP PCF8591 ADC/DAC and Microchip 24LC512 EEPROM. | ||
- | These were chosen because they add useful capabilities to the ESP-01 or RPi and all three are available in DIP format from CPC in the United Kingdom. | + | These were chosen because they add useful |
+ | You may also consider adding an I2C RTC to this project and perhaps it shall be updated to include one at a later time. | ||
=== Schematic === | === Schematic === | ||
- | The circuit is expected to be used with either an ESP-01 attached and with it' | + | The circuit is expected to be used with either an ESP-01 attached and with its UART connected to a computer to load in scripts, else without an ESP-01 and with the I2C lines connected to a Raspberry Pi. |
{{: | {{: | ||
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=== I2C bus === | === I2C bus === | ||
- | The I2C bus is simple affair with only two lines required for it' | + | The I2C bus is simple affair with only two lines required for its operation. This is perfect for the ESP-01 module which only has two GPIOs exposed on its header pins. For the Raspberry Pi, there are two I2C buses, but only one is normally available. |
^Address ^Device | | ^Address ^Device | | ||
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I2C EEPROMs have varied addressing schemes. The simplest is a 8-bit address offset, another one where a block selection is made with an I2C address and a byte selection is made with an 8-bit address offset. Yet another, where the I2C address is fixed but it now has a 16-bit address offset and lastly one with both of the last methods combined. | I2C EEPROMs have varied addressing schemes. The simplest is a 8-bit address offset, another one where a block selection is made with an I2C address and a byte selection is made with an 8-bit address offset. Yet another, where the I2C address is fixed but it now has a 16-bit address offset and lastly one with both of the last methods combined. | ||
- | The 24LC512 | + | The 24LC512 |
== ESP-01 NodeMcu == | == ESP-01 NodeMcu == | ||
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238 | 238 | ||
</ | </ | ||
- | |||
- | eSPY is still being developed and as yet doesn' | ||
== RPi == | == RPi == | ||
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[[http:// | [[http:// | ||
[[http:// | [[http:// | ||
+ |