Showing posts from November, 2021

Azure IoT and M5Stack with M5Flow Blocky Python - D2C

Device to Cloud (D2C) with Azure IoT Hub I've been playing with the M5Stack Core2 devices and wanted to see how hard it would be to create a program that could send data to Azure without having to actually write any code.  I used the M5Flow (blocky) graphical program builder. It includes common cloud blocks for Azure and AWS.  The program sends sensor data to Azure IoT where it can be processed. I only verified the messages were received in Azure.  Processing will be left for another time. There weren't a lot of samples out there. I hope this will help others can use this as a starting point. You can find a link to a video walkthrough down below. Azure IoT Hub Device-to-Cloud From the Microsoft guide When sending information from the device app to the solution back end, IoT Hub exposes three options: Device-to-cloud (D2C) messages for time ser

Azure IoT Hub - Generating the SAS Token connection string

IoT devices identify themselves by presenting credentials when they connect to an IoT hub.  Unique credentials are burned into each IoT device. The simplest way to prototype IoT Hub connected devices is to use Shared Access Signature Tokens.  SAS Tokens are created by signing configuration information with the device's symmetric key that was generated when the device was provisioned in the IoT hub. There are several different ways to manage device credentials on the device itself. Embed the Symmetric key in the device and have the device generate the token. This has the advantage of letting the device refresh its tokens. It has the disadvantage that the symmetric key has been installed on a device that you can lose control of. Embed the SAS Token directly in your device if the device does not have a library to generate them. This has the advantage of not needing the signing library. It has the disadvantage that you have hard-coded a future death date into the device wit

The AWS IoT EduKit IoT - An M5Stack with a secure element for AWS Integration

AWS and Microsoft have both been busy demonstrating how their clouds are ideal for fleets of IoT devices.  Both introduced their own sample hardware.  The AWS entry is an M5Stack Core2 ESP32 device that comes with I/O, ports, and a certificate store.  Amazon has a couple relatively straightforward examples including a simple "blinking light" program that reacts to cloud messages with lights and that sends regular messages to cloud topics for processing. I created the video down below to give a quick overview of the steps that make up that sample. AWS Branded IoT Device This is the device.  It is an AWS-enhanced version of the standard M5Stack Core2 component. The Demo Application The sample program operates on two paths. It sends a regular message to AWS via MQTT.  The sample tells you how to view that message in the AWS portal. The sample then shows you how to use the IOT test client to generate test messages that are sent to the EduKit IoT device.  The devi

Crypto mining with LHR cards - the T-Rex dual mining effect

Crypto mining is something I read about but have never played with. I've read about how it works and how NVidia implemented an LHR limited hash rate to reduce the utility of their graphics cards for mining.   The T-Rex project recently came out with a new version that bypasses much of the LHR by using the graphics card to mine two currencies at the same time. This lets you mine both currencies with transaction rates below the rate limit. NiceHash QuickMiner / Excavator This is my default miner that is easy to set up and easy to run with no installation.  It gives you good results with no custom setup required.   A single ethash miner running on my NVidia RTX 3080 TI generates about  52MH/s Sample payout  The right way to do a comparison is to compare hash rates at the same time and not BTC/24 hours across two different times.  We should run two rigs at the same time using two different configurations.  I only have one graphics card so I used two different time windows.   This graph

Bitlocker requires a code whenever you change hardware signature - a graphics card

Bitlocker forces you to re-enter our BitLocker encryption key when a drive has been moved to different hardware.  Upgrading a graphics card will change the signature.  This means a graphics card upgrade may prompt you for your BitLocker key on startup. You will be prompted for your key.   Hopefully, you saved your BitLocker key to your Microsoft account to paper or some secure device. Microsoft provides the corporate recovery link The boot screen refers you to .  This is the location redirects to htts:// where Enterprise Accounts  keep their BitLocker keys.  You will get a message something like  AADSTS50020: User account <your account> from identity provider '' does not exist in tenant 'Microsoft' and cannot access the application ....(MSProtect Website [wsfed enabled]) in that tenant. The account needs to be added as an external user in the tenant first. Sing out and sign in again with a different Azure