RST Decoder Pro vs arduinoSG90
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RST Decoder Pro
This application decodes Morse code from your device's microphone, offering two decoding methods (BPF and FFT) with adjustable parameters. It includes features like automatic frequency detection, gain control, and real-time signal display for accurate Morse code practice and reception.
- Microphone Morse code decoding
- BPF and FFT decoding methods
- Auto Frequency Detector (AFD)
- Auto Gain Control (AGC)
- Real-time CW signal display
- Waterfall display (Pro version)
- Adjustable control parameters
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This is an App that decodes Morse code input from the microphone. I recommend that you try the basic functions and usage with the free version before purchasing. It is a Morse practice App that you can use to check if you are keying the correct code. Signals with good S/N can be decoded correctly, but signals with bad S/N cannot be decoded correctly. Also, the performance will be degraded for extremely slow or fast signals. Usually about 5 to 10 characters are required for speed synchronization of Morse Code. Adjust the input signal so that the peak value changes from level 6 to level 7. Make fine adjustments to each parameter according to the reception status. [Additional Functions] -In addition to the decoder using BPF, a new decoder using FFT has been added so that it can be switched according to the usage. -AFD (Auto Frequency Detector) function has been added to the decoder using BPF, and BPF can be set automatically by pressing the AFD button. -The decoder using FFT automatically follows the strongest signal in the band by AFD (Auto Frequency Detector) and AGC (Auto Gain Control). You can also hold the AFD / AGC parameters by pressing the Lock button. * There will be a time lag of about 1 to 2 seconds for AFD tracking. * The Pro version also supports waterfall display. [Control parameters] 1.Language select English and Japanese(KANA) 2.Audio Input Level 3.BPF ON/OFF 4.BPF of Center Frequency 5.BPF of Band Width 6.BPF of Shape 7.Notch ON/OFF 8.Notch of Center Frequency 9.CW Speed Control ON/OFF 10.CW Speed Control Low, Mid1, Mid2 or High 11.Delete All Decoded Text 12.Realtime CW Signal Display 13.Input signal recording function. 14.Playback function from the file list. 15.Support the Garbage Data reduction function [Note] Since the signal after BPF is output to the audio output, it can also be used as an AF-CW filter. [URL of this App(Free version) working example video] The GUI is slightly different, but the basic functionality is the same. https://youtu.be/Pwp7W4m-m34
arduinoSG90
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This application is for controlling the SG90 servo connected to the Arduino ESP8266 family. Therefore, an Arduiono ESP8266 and SG90 servo are required in advance, and a program must be written to the ESP8266. Please refer to the source code for program samples. This is a program that sends String data to arduino ESP8266 by UPD. Please see below for the program on the arduino side. https://ios.iya.tokyo/031udp/ If the source remains the IP address is 192.168.4.1 port 8888 I think it will be It can be operated as below https://youtu.be/M9JkJ-v0i4E
Screenshots
Verdict
The clearest difference is price: arduinoSG90 at Free against RST Decoder Pro's $1.99. arduinoSG90 also leads on update cadence (daily vs monthly). On ads, in-app purchases, device support and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
arduinoSG90 is free to download; RST Decoder Pro costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
RST Decoder Pro ships an update monthly, arduinoSG90 daily. The most recent releases landed on October 6, 2026 and October 7, 2026 respectively.
| Parameter | RST Decoder Pro | arduinoSG90 |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Monthly | Daily — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone | iPhone, iPad — better |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 1 MB | 3 MB |
| Age rating | 17+ | 4+ |
| Developer | koji kamogawa | YASUYUKI INUKAI |
In-app purchases
RST Decoder Pro
No in-app purchases
arduinoSG90
No in-app purchases
Questions
Is RST Decoder Pro free?
Is arduinoSG90 free?
Do RST Decoder Pro or arduinoSG90 have ads?
Which is updated more often, RST Decoder Pro or arduinoSG90?
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