HAccess System

The Hackspace Infastructure
1

Hi All,

I know that we can’t fit the lock to the inner door until we get the new HAccess system up and running
So I had a quick look at the schematics to try and figure out if there was anything I could do

I’ve not spoken to Ben or Bob over this just yet, but I’m wondering if one of the problems might be that we’re trying to squeeze too much onto the ESP Wifi device
since it looks like it’s also being used the main processor.

A couple of ideas I came up with

First replace the MCP2300 Bus expander with a ARM Cortex M0 - http://uk.farnell.com/stmicroelectronics/stm32f030c8t6/mcu-32bit-cortex-m0-48mhz-lqfp/dp/2393634

  • You might get some more IO pins
  • I think the cost isn’t that much different (90p vs £1.50 plus a crystal)
  • SWD Debugging with a small connector (ether 10 pin or STLink)
  • use of mbed-os to connect to the PN532 / Display
  • ESP can be used just for wifi
  • 64K of Ram

For the display you could switch the Noka 5110 with an Oled one instead

Oleds tend to look cooler than LCD’s but I think you can’t have them powered all the time because of the lifetime of the device (around 14,000 hours)
In that they display something after a change but then switch off after a min or two

From a cost point of view it’s probably only an extra £1 or £2, for remote debugging I’d say it’s worth it though.
If there’s some interest then I might get one of those PN532 modules and a oled display to play around with, since I’ve already got some other bits.

2

Hi, thanks for looking at this:

  • I have already started with an STM32 device to replace the IO expander,
    the code hasn’t been uploaded yet.
  • The STM will provide an ESP watchdog and hard power the ESP8266
  • It will provide IO lines for control of backlight and outputs (maybe
    buttons too)
  • It will run the SPI link to the display (ease of routing)

The ESP8266 has pleanty of code room, the issues have been with card reading
which we first thought was I2C comms, but turns out to actually be the
reader modules
we’ve been using. The red modules will read standard tags fine but won’t
read any of
the oyster/bank/etc cards. We have source a few of the blue ones which do
seem to
work, but we lost a lot of time with this.

We are considering making a veroboard(or similar) quick prototype for the
inner
door mostly copying the one I made a few weeks ago, with one of the stm
neucleo
boards and a nodemcu.

Display wise, we can consider options when we get round to making a new
board,
the OLED are ok, but there are some ok colour nokia LCDs as well

3

On the stm32 front, we’ve already selected one of the lqfp32 devices as
they’re easier to solder.
There’s no need for a crystal, the internal RC is fast enough to run the
device.
I’ve already done some of the i2c handling code using the stm32 libraries.

4

Ah okay
One of the reasons I mentioned mbed-os is because it has a python script that make library management and compiling a lot easier / cross platform
For the PN532 I found some libs here

For the programming interface

I’m in the process of writing some blog entries on flashing with different tools, and debugging with different ide’s at the moment.