Tech – Rebelbot

17Oct2015/12/04

Workshop: Optimizing Code For Memory and Performance

This workshop I have created goes by a few different names:

How to Squeeze a Processor for Memory and Performance

or the longer name:

Squeezing Blood From A Stone: Getting Back Memory and Performance

Regardless of what name got you here, it will debut in less than a month at Hack A Day’s Super Conference November 14th & 15th. It will happen Sunday the 15th 12:15am.

We’ll guide you though a series of labs to explain how to measure performance and memory, then the basics of improving them based on your goals.

Since this is a hands on but very short workshop focusing on using the following free tools (Download and install it yourself BEFORE the workshop or you’ll be sad) and cheap hardware:

Windows-enabled computer (MacOS with bandcamp or other VM could probably work)
Github repo or the project on my HackADay profile.
Keil MDK-Lite v5.16a for ARM Cortex free version (limited to 32kB)
- Install the STMicroelectronics STM32L4 Series Device Support, Drivers and Examples pack from here
IDA demo from Hex-rays
STM32L476 Discovery Board (Provided by workshop or here)
(2 items here)ST-LINK V2 SW (util, driver, and firmware update)
(Optional) Portable logic analyzer/oscilloscope.

Squeezing Blood From a Stone V1.2 from Jen Costillo

29Jul2015/10/17

108: Ne-Ne-Nebarious

I went back to talk with El and Chris about wearables and IoT security (Check the link for even more info) in advance of the Embedded Systems Conference Silicon Valley. I’ll probably get the slides up soon.

Meanwhile, I am interested in getting back to doing choreography fused with technology. I was really impressed with this years tech program that Ballet Silicon Valley did and missed my own work. I am also interested in learning and sharing with others, so I am putting out the call for collaborators on either end by emailing at this domain to the info@ account. See more at http://catmachinesdance.com.

26May2015/05/26

Getting Your Bitmaps Converted for Simple Display in Your Firmware

Perhaps you finally got a snazzy display for your latest project. I highly recommend the AdafruitGFX library as well as GIMP, and for making your own fonts, MikroElcktronika GLCD Font Creator (optional and not covered here).

If you are looking for a project to get you started, AdaFruit has a lovely wearable project.

Setup

GIMP
Access to your lovely bitmaps

Process

Open the target bitmap into GIMP.
Assume it is trimmed to the size you desire.
Take note of the dimensions of the bitmap
From the GIMP menu, select Colors->Rearrange colormap so it is appears a below (BLACK = 1; WHITE = 0) and click OK.

Select from the menu Image->Mode->Indexed. Choose 1-bit palette and click “” Dithering is optional.

Save the file by selecting File->Export As. Choose c header file (.h) and name appropriately. Now use this however needed in your required firmware infrastructure. Personally, I make sure everything is “const” and indexable with sizes and offsets.Here is an example(rebelbot_bw.h).