# ESP32-C3 ADS1115 pH ORP Sensor Interface 4412 ## Description ESP32-C3 battery-powered pH and ORP probe interface using ADS1115 differential ADC, MCP6002 through-hole buffers, DS18B20 temperature compensation, and short net labels for firmware handoff. ## Project Details - **Owner:** sudarakalakshitha - **Created:** 7/10/2026 - **Last Updated:** 7/11/2026 - **Visibility:** Public - **Domain:** Sensor - **Operating Voltage:** 3.3V - **Software:** Arduino - **Connectivity:** I2C - **Power Requirements:** Battery - **Copies:** 1 ## Key Components ### J1 — [CONBNC001](https://www.flux.ai/vasy_skral/conbnc001~qj8.md) - Part Type: Connector - Manufacturer Name: TE Connectivity Linx - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: 5-pin through-hole BNC matching user's connector photo: center=PHE, four shield/mechanical pins=PHR biased near 1.65V, not GND. - Datasheet URL: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=CONBNC001&DocType=Data+Sheet&DocLang=English&DocFormat=pdf&PartCntxt=CONBNC001 - Role: Sensing (Shunt) - Manufacturer Part Number: CONBNC001 **Pins:** - GND [pin S2] - GND [pin S3] - GND [pin S1] - GND [pin S4] - Signal [pin 1] ### J2 — [Pin Header 01x08 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-01x08-254mm-vertical~4nq.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: External controller header replacing onboard ESP32-C3: Pin1=3V3, Pin2=GND, Pin3=SDA, Pin4=SCL, Pin5=ALT/ADS1115 ALERT, Pin6=ADR/ADS1115 ADDR control, Pin7=DQ/DS18B20 data, Pin8=GND. - Role: Interface - Part Type: Connector **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] - 7 [pin 7] - 8 [pin 8] ### J3 — [Pin Header 01x03 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-01x03-254mm-vertical~cp4.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Waterproof DS18B20 temperature probe header: pin 1=3V3/red, pin 2=DQ/yellow or white, pin 3=GND/black. - Role: Sensing (Shunt) - Part Type: Connector **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] ### J4 — [Pin Header 01x02 2.54mm Vertical](https://www.flux.ai/jharwinbarrozo/generic-pin-header-01x02-2p54mm-vertical~4uy.md) - Role Details: Optional duplicate 2-pin DS18B20 data/debug header: P1=DQ, P2=GND. - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector - Role: Sensing (Shunt) **Pins:** - P1 [pin 1] - P2 [pin 2] ### J5 — [CONBNC001](https://www.flux.ai/vasy_skral/conbnc001~qj8.md) - Role Details: 5-pin through-hole BNC matching user's connector photo: center=ORE, four shield/mechanical pins=ORR biased near 1.65V, not GND. - Part Type: Connector - Manufacturer Name: TE Connectivity Linx - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=CONBNC001&DocType=Data+Sheet&DocLang=English&DocFormat=pdf&PartCntxt=CONBNC001 - Role: Sensing (Shunt) - Manufacturer Part Number: CONBNC001 **Pins:** - GND [pin S2] - GND [pin S3] - GND [pin S1] - GND [pin S4] - Signal [pin 1] ### J6 — [Pin Header 01x04 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-01x04-254mm-vertical~l97.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: External power module header: Pin1=USB5 from TP4056 charger input, Pin2=BAT 18650/protected battery node, Pin3=3V3 regulated sensor rail, Pin4=GND. Do not use MP1584 for single-18650 to 3V3; use ESP32 3V3 output or a low-Iq buck-boost/LDO module. - Role: Power Conversion - Part Type: Connector **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] - Pin_4 [pin 4] ### SW1 — [1101M2S3CQE2](https://www.flux.ai/openpartlist/1101m2s3cqe2~sp.md) - Role Details: Through-hole master on/off switch; wired as SPST to cut switched 3V3 system rail including ESP32, ADS1115, pH/ORP analog front end, DS18B20, pull-ups, and RGB/status LED loads. - License: https://creativecommons.org/licenses/by/4.0/ - Connector Type: Power Connectors - Role: Switching - Manufacturer Part Number: 1101M2S3CQE2 - Part Type: Switch - Datasheet URL: https://www.ckswitches.com/media/1429/1000.pdf - Manufacturer Name: C&K **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] ### U2 — [MCP6002-I/P](https://www.flux.ai/adrian95/mcp6002-ip~t3o.md) - Part Type: Operational Amplifier (OP-AMP) - Package or Case Code: DIP781W56P254L950H533Q8N - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: MCP6002-I/P - Datasheet URL: https://ww1.microchip.com/downloads/en/DeviceDoc/MCP6001-1R-1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf - Role Details: Through-hole DIP-8 MCP6002 at 3V3: U2A buffers pH input, U2B buffers VBD into VBI for pH reference/bias. - Manufacturer Name: Microchip - Role: Amplification **Pins:** - VDD [pin 8] - VINA- [pin 2] - VINA+ [pin 3] - VINB- [pin 6] - VINB+ [pin 5] - VOUTA [pin 1] - VOUTB [pin 7] - VSS [pin 4] ### U3 — [MCP6002-I/P](https://www.flux.ai/adrian95/mcp6002-ip~t3o.md) - Package or Case Code: DIP781W56P254L950H533Q8N - Part Type: Operational Amplifier (OP-AMP) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: MCP6002-I/P - Datasheet URL: https://ww1.microchip.com/downloads/en/DeviceDoc/MCP6001-1R-1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf - Role Details: Through-hole DIP-8 MCP6002 at 3V3: U3A buffers ORP input, U3B buffers VBD into VBO for ORP reference/bias. - Role: Amplification - Manufacturer Name: Microchip **Pins:** - VDD [pin 8] - VINA- [pin 2] - VINA+ [pin 3] - VINB- [pin 6] - VINB+ [pin 5] - VOUTA [pin 1] - VOUTB [pin 7] - VSS [pin 4] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/sudarakalakshitha/esp32-c3-ads1115-ph-orp-sensor-interface-4412~ms](https://www.flux.ai/sudarakalakshitha/esp32-c3-ads1115-ph-orp-sensor-interface-4412~ms).* --- *Generated from [https://www.flux.ai/sudarakalakshitha/esp32-c3-ads1115-ph-orp-sensor-interface-4412~ms](https://www.flux.ai/sudarakalakshitha/esp32-c3-ads1115-ph-orp-sensor-interface-4412~ms)*