Adam Fabio writes on the Hackaday blog:
As an entry into this year’s Best Product portion of the Hackaday Prize, [kelu124] is developing a hardware and software development kit for ultrasound imaging.
Ultrasound is one of the primary tools used in modern diagnostic medicine. Head to the doctor with abdominal pain, and you can bet you’ll be seeing the business end of an ultrasound system. While Ultrasound systems have gotten cheaper, they aren’t something everyone has in the home yet.
[kelu124] is working to change that by building a hardware and software development kit which can be used to explore ultrasound systems. This isn’t [kleu124’s] first rodeo. HSDK builds upon and simplifies Murgen, his first open source ultrasound, and an entry in the 2016 Hackaday prize. [kelu124’s] goal is to “simplify everything, making it more robust and more user-friendly”.
The system is driven by a Raspberry Pi Zero W. A custom carrier board connects the Pi to the pulser block, which sends out the ultrasonic pings, and the analog front end, which receives the reflected signals. The receiver is called Goblin, and is a custom PCB designed [kelu124] designed himself. It uses a variable gain amplifier to bring reflected ultrasound signals up out of the noise.
We haven’t tapped yet into the full potential of the Raspberry Pi in terms of ADC. Some have shown that the first gen of Raspberry could go to 10Msps [..] My take is that the new Raspberry Pi’s can surely go above. And I want to try it, either with this old CA3306E or with more recent kick-ass ADCs.
The design files are available on GitHub:
Eric Brombaugh designed this ADC board for RF signals:
This is an ADC designed for use in digitizing RF signals with up to 40MHz bandwidth and 80dB SNR. The form-factor is compatible with a dual-connector Digilent Pmod so that it can be used with commonly available FPGA development boards to build a variety Software-Defined radio functions.
- ADC14C105 14-bit 105MSPS RXADC.
- Onboard 3.3V Regulator (5V input)
- Filtered Analog 3.3V Supply
- Onboard 80MHz clock oscillator
- Digilent-compatible 2-connector Pmod interface
- 50-ohm SMA input – 2.5Vpp ~= 0dBfs
emeb has shared the board on OSH Park:
Piotr Zapart designed this board to overcome range issues when using traditional 300 degree potentiometers or Hall sensors as rotational angle to voltage converters:
The idea was to create a device that will perform an axis calibration, usually done in digital domain, but before sampling the signal in the ADC, still in analog domain, using it’s advantageous infinite resolution
the main function of this device is to:
- Buffer the analog output signal coming from a potentiometer or another rotary angle to voltage converter like ie. Hall sensors.
- Filter out the high band noise and limit the bandwidth to an usable range only, protect the input against voltage spikes.
- Match the output voltage range of the source (pot/hall sensor) with the input range of the ADC, thus making the most of the available ADC resolution.
- Linearize the hall sensor output signal response by amplyfing it’s most linear region to the full scale ADC input range.
The board is shared on OSH Park: