Esp8266

 

Catching up with the latest ESP8266_NONOS_SDK_V2.0.0_16_07_19

– got into some issues.

Seems like Espressif integrated some time compatibility functions into libmain.a which i already had into the tree, most likely due mbed tls port

If you have millis(), micros(), mktime() and friends then you may need to comment them out.

There is one exception – open soruce xtensa gcc provides time() which is required by ANSI C so it is in  – platform must provide gettimeofday.
The problem is time() is in libmain from the SDK – so the workaround is to strip time from your libc and use the one in the SDK.

Espressif announced on 05/11/2015 the upcoming ESP32 chip:

 

While the specs are impressive a lot of questions a rise :

• Support – Espressif is a small company as far as we knew – would they be able to support both chips in the long term?
• Compatibility with esp8266?  – The new ESP32 will use the RTOS based SDK and most APIs are said to be compatible with the esp8266 SDK.
• Price – The price will be higher than esp8266  but not much higher.

Beta testing program is coming soon.

A Teaser of What to expect from our upcoming WiFi connected 2 channel relay board.

Web UI of the relay board

Main control screen and part of the configuration

Main control screen

Part of the configuration

Schedule editor

While working on a secure cloud for the gang of the esp8266 based devices we are developing we need SSL – real and secure.

And this August is the month of the SSL issues , it seems , but thankful to the Espressifs’ quick support they are on the way out.

SSL Memory Leak

The latest SDK v1.3.0 introduced a bug that simply didn’t call the disconnect callback of esp connections under some circumstances and that in turn leaked memory.  It’s not clarified but the case was when you had a tcp listener and ssl connection after the ssl connection is over, your tcp listener connections did receive disconnect callbacks anymore.  You can get the fix from bbs.espressif.cn

During the past weeks i’ve worked on getting the FOTA upgrades work on the 2MB boards by Olimex.

The wonderful esp-link project by Thorsten von Eicken was a great example of  two things:

1. How to concatenate the espfs filesystem image with the firmware images.
2. How to properly write a new image to the flash.

It was a nice example to start with.

So after a lot of fiddling with  Makefiles, cgi routines and esptool  – i’ve finally got the OTA working.

Engineering Internet Of Things Secure network  for our upcoming IoT service.

Goals:

• Security
• Redundancy
• End to End Security
• Secure Firmware Upgrades

Threats:

• DoS Attacks
• DDoS Attacks
• DNS spoofing /don’t even think of DynDNS/
• Sniffing
• man in the middle

Security:

• Using a VPN -> takes the problem away and requires extra settup. Not user friendly. The only pro is that it can use an existing infrastructure if present. A Big NO
• SSL -> expired certificates , heavy overhead, often exploited. Closed source library, may already be hacked. NO
• AES all the Way. A big YES
• DoS/DDoS prevention – redundant MQTT brokers, with dns/firmware fallback

So Why AES?

Which goes where – when using a bootloader for FOTA.

The files:

• master_device_key.bin –  Obtained from Espressif Cloud
• esp_init_data_default.bin – Stores default RF parameter values
• boot.bin – bootloader
• user1.bin and user2.bin – user firmware
• blank.bin – blank settings , flash to get default parameters

1. 512KB

• master_device_key.bin 0x3E000
• esp_init_data_default.bin 0x7C000
• blank.bin 0x7E000
• boot.bin 0x00000
• user1.bin 0x01000
• user2.bin 0x41000

2. 1024KB Flash

• master_device_key.bin 0x3E000
• esp_init_data_default.bin 0xFC000
• blank.bin 0xFE000
• boot.bin 0x00000
• user1.bin 0x01000
• user2.bin 0x81000

3. 2048KB Flash

• master_device_key.bin 0x3E000
• esp_init_data_default.bin 0x1FC000
• blank.bin 0x1FE000
• boot.bin 0x00000
• user1.bin 0x01000
• user2.bin 0x81000

4. 4096KB Flash

• master_device_key.bin 0x3E000
• esp_init_data_default.bin 0x3FC000
• blank.bin 0x3FE000
• boot.bin 0x00000
• user1.bin 0x01000
• user2.bin 0x81000

 

I need a bigger flash and a breadboard friendly board. Quick research lead to the following variants, beside soldering a bigger flash on the ESP-XX series modules.

1. NodeMCU board’s that have bigger flash and fit on a breadboard but have regulators and usb 2 serial on them.
2. ESP-XX module with adapter,  don’t like .
3. MOD-WIFI-ESP8266-DEV

And the winner is Olimex’s – MOD-WIFI-ESP8266-DEV .

i got some of them:

Hi,

A simple i2c driver for the Microchip’s TCN75A thermometer – supports up to 8 thermometers. Driver works in one shot mode which is suitable for battery powered operations. The chip is with quite good specs for its price.

Code at github esp_i2c_tcn75a .

Usage:  checkout user/user_main.c for example usage.

Enjoy!

73

 

After a lots of lots of wasted hours  debugging an I2C driver it came out that the noise from the connected cheep USB2TTL converter is way too much. Would have lost months without the help of the new DS1054z scope i’ve got.

So i came up with this – a simple UDP debugging.

Simple socket to send udp messages.

dbg

Call dbg_udp_start(0) and you are ready to go. If you prefer not to flood your LAN with debug messages broadcasts then instead of 0 provide your workstation IP address.