Documentation

ShillehTek 24MHz 8 Channel USB Logic Analyzer Digital Debugger for Arduino | ShillehTek Product Manual
Documentation / ShillehTek 24MHz 8 Channel USB Logic Analyzer Digital Debugger for Arduino | ShillehTek Product Manual

ShillehTek 24MHz 8 Channel USB Logic Analyzer Digital Debugger for Arduino | ShillehTek Product Manual

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Overview

This 24 MHz 8-channel USB logic analyzer is the cheapest possible upgrade from "blink an LED to debug" to actually seeing what your digital signals look like. Plug it into a USB port, hook the eight color-coded test leads onto your I2C / SPI / UART / 1-Wire lines, and watch every transition appear in software like Saleae Logic, sigrok / PulseView, or fx2lafw.

It's based on the popular Cypress CY7C68013A USB controller and emulates the original Saleae Logic 8-channel analyzer at the protocol level — meaning you can use the official (free) Saleae Logic software OR the open-source PulseView with full protocol decoders for I2C, SPI, UART, CAN, 1-Wire, JTAG, and dozens more. Sample rates up to 24 MS/s mean you can see SPI buses up to ~10 MHz cleanly.

At a Glance

Channels
8
Max Sample Rate
24 MS/s
Input Voltage
0 - 5.25V
Logic Threshold
~1.4V
Interface
USB 2.0
Dimensions
56 × 27.6 × 20.3 mm

Specifications

Parameter Value
USB Controller Cypress CY7C68013A (EZ-USB FX2LP)
Channels 8 digital inputs
Maximum Sample Rate 24 MS/s (single channel) / 12 MS/s (8 channels)
Recommended Signal Frequency ≤ 8 MHz for clean capture
Input Voltage Range 0V - 5.25V
Logic Threshold VIH ~ 2.0V (HIGH), VIL ~ 0.8V (LOW)
Input Impedance ~100 kΩ in parallel with ~10 pF
Buffer / Memory Streaming via USB (no onboard memory)
Interface USB 2.0 Mini-B (cable included)
OS Support Windows / macOS / Linux (via Saleae or sigrok)
Power Bus-powered (USB 5V, < 100 mA)
Dimensions 56 × 27.6 × 20.3 mm

Pinout Diagram

24MHz 8-channel USB Logic Analyzer with labeled CH0-CH7 channels and GND pins

Wiring Guide

Probing an I2C Bus

I2C only needs two channels. Connect a third lead to GND so the analyzer shares a reference with your circuit.

Analyzer Connect To
CH0 (black) SDA
CH1 (brown) SCL
GND (gray) Circuit GND
Tip: In PulseView, enable the I2C decoder on CH0 (SDA) and CH1 (SCL). You'll see decoded address bytes, ACK/NACK, and data right above the waveforms.

Probing an SPI Bus

SPI is 4-wire. The analyzer shows MOSI, MISO, SCK, and CS clearly so you can verify your transfers byte-by-byte.

Analyzer Connect To
CH0 SCK
CH1 MOSI
CH2 MISO
CH3 CS / SS
GND Circuit GND
Warning: SPI buses commonly run at 1-10 MHz. The analyzer is reliable at up to ~8 MHz when sampling at 24 MS/s with all 8 channels active. For 16+ MHz SPI you need a faster analyzer.

Probing UART (Serial)

For unidirectional UART you only need TX. For full duplex add RX. Always tie GND.

Analyzer Connect To
CH0 TX (from device)
CH1 RX (from host)
GND Circuit GND
Tip: In PulseView, the UART decoder asks for baud rate. If you don't know it, try common values (9600, 115200, 460800) until you see ASCII text instead of garbage.

Channel / Wire Color Map

Channel Wire Color
CH0 Black
CH1 Brown
CH2 Red
CH3 Orange
CH4 Yellow
CH5 Green
CH6 Blue
CH7 Purple
GND Gray (or White)

Code Examples

The logic analyzer doesn't run code itself — your microcontroller does, and the analyzer captures the resulting signals. Below are setup commands for the two most popular software options.

Saleae Logic (Free, Windows / macOS / Linux)

Setup steps
# 1. Download Saleae Logic v1.2.x ("Legacy") from saleae.com/downloads
#    The newer Logic 2 software does NOT support clones - use Logic 1.x.
# 2. Plug in the analyzer via USB.
# 3. Open Logic. It auto-detects "Saleae Logic 8".
# 4. Click the gear next to a channel to enable an analyzer (I2C, SPI, etc.)
# 5. Hit Start to capture.

sigrok / PulseView (Free, all platforms)

install_pulseview.sh
# Linux:
sudo apt install pulseview sigrok-firmware-fx2lafw

# macOS (Homebrew):
brew install pulseview sigrok-firmware-fx2lafw

# Windows: download installer from sigrok.org

# Plug in the analyzer.
# Open PulseView -> Connect to Device -> "fx2lafw" driver ->
#   "saleae-logic" or "Cypress" -> Scan -> Select device.
# Set sample rate to 8 or 16 MS/s for typical buses.
# Add decoders by clicking the green "Add protocol decoder" icon.

Linux — Quick I2C Capture from CLI

capture_i2c.sh
#!/bin/bash
# Capture 5 seconds of an I2C bus on CH0 (SDA) and CH1 (SCL)
# Output as a .sr file you can open in PulseView later

sigrok-cli --driver fx2lafw --config samplerate=8m \
  --channels D0,D1 --time 5000 --output-format srzip \
  --output-file i2c_capture.sr

Frequently Asked Questions

Will the new Saleae Logic 2 software work with this?
No. Saleae Logic 2 only supports their newer hardware. For this 24 MHz analyzer you need either Logic 1.2.x (legacy, free, still works great) or PulseView. Both are free.
What's the maximum signal frequency I can probe?
Nyquist says signal ≤ sample rate / 2, but in practice you want at least 4× oversampling for clean edges. So at 24 MS/s, signals up to ~6 MHz are clean. Pushing to 8-10 MHz works but you may miss thin glitches.
Why is my capture showing all zeros?
Almost always missing GND. The analyzer needs a ground reference shared with your circuit. Connect at least one of the gray/white GND leads to your circuit's GND. Also confirm the leads are actually touching the right pins (not just hovering near them).
Can it probe 3.3V signals?
Yes. The logic threshold is around 1.4V, so any signal that swings between 0V and 3.3V (or 1.8V, or 5V) is read cleanly. The maximum input is 5.25V — never feed it negative voltages or anything above 5.25V.
Does it have onboard memory or just stream?
Pure streaming over USB — no onboard memory. That means USB hiccups can cause sample drops at the highest rates. For long captures, use a fast direct USB port (not a hub) and 8-12 MS/s for stability.
Can I use it as a protocol injector / send signals?
No — it's input-only. For both reading and writing buses, look at the Bus Pirate or any FT2232H-based "active probe" boards. This analyzer is for observation only.