Quick Start Guide - DeeEmm/DIY-Flow-Bench GitHub Wiki

If you are already familiar with the ESP32 platform or already have your programming environment setup to handle the ESP32 platform, you can jump right in with this quick start guide.

Requirements

DIYFB runs on the ESP32 platform. We recommend using the Wemos D1 as this is compatible with the official DIY-Flow-Bench shield, but you should be able to easily port the code to any other ESP32 board with at least 4meg of memory.

Hardware setup

Bare bones setup

Out of the box the DIYFB controller is set up to work with the BOSCH_0280218067 (AUDI RS4) MAF sensor. No other sensors are required to be able to generate flow readings. Temperature, Humidity and Barometric sensor readings can be set to a fixed value that can be configured in the GUI. However, Temperature, Humidity and Barometric sensor values are required to convert from Mass flow to volumetric flow._

If you want to use a different MAF sensor, it is worth familiarising yourself with the MAF Data page as there are some caveats to be aware of.

Recommended setup

As a minimum the BME280 environmental sensor, with a MAF sensor connected to an analog input will generate usable results and allow you to view the results in CFM. The drawback here is that the ESP32 only has a 12 bit ADC and so input resolution is inferior compared to running a dedicated ADC.

The recommended setup is therefore to use an ADS1115 ADC. This has a 16 bit resolution. To be able to hook this up to the ESP32 along with the BME280, you will need to use a logic level shifter such as the PCA9306. This is to allow the ADS1115 to run at 5volts to match the MAF sensor signal voltage, whilst still being able to connect to the ESP32 and BME280, which are both 3.3v devices.

Additional sensors.

The reference pressure sensor is not needed to read the flow from the MAF sensor, however it is advisable to consider using one if you want to ensure repeatable results or compare your results with other benches. It will also allow you to display in standardised units. Being able to use a repeatable reference pressure ensures that all of your tests utilise the same parameters which eliminates environmental factors. The Reference pressure sensor can be connected to input 2 of the ADS1115

The addition of the reference pressure sensor along with temperature, humidity and barometric pressure also allows you to use the conversion features built into the software, this includes converting between reference pressures, international standards and converting from mass flow (kg/h) to volumetric flow (cfm) which is a more meaningful metric. If you are using fixed values for these sensors then you will need to ensure that the values are correct at the time of undertaking your test, which means that you will need to correct these values at a minimum each time you use your bench. Obviously the best solution is to consider integrating these additional sensors into your build so that these values are always current and accurate.

Differential Flow Benches

If you are using the DIYFB controller on an orifice or pitot style bench then the additional sensors along with a differential pressure sensor are required to be able to calculate the flow values. The MAF sensor is not needed.

All sensors are supported on the official DIYFB Shield.

Software setup (RC9 onwards)

  • Download the current DIYFB release from the Releases page.
  • Compile and upload the code to the board.
  • Power up the board.
  • Join the AP WiFi network called "DIYFB". (The password is "123456789").
  • Visit http://diyfb.local in your browser or the IP address shown in the serial monitor on boot.
  • You can now access the DIYFB app.
  • Next: set the appropriate I/O pins on the PINS page and edit the bench settings and hardware configuration in accordance with your setup.
  • Reset the board.
  • Refresh your browser.
  • If you want the DIYFB to join your local WiFi network you can edit the SSID and WiFi password details on the settings page.

If for some reason you have issues changing the WiFi credentials or setting the pins, you can reset them to the default values using the Serial API. Just issue the following commands to the Serial Monitor

'%' - Reset AP WiFi data
'&' - Reset Pins.

You can also view a full list of API commands by issuing the '?' command.

'?' - View API Help