I am having the same problem! I have an IPhone 7Plus and message keeps saying accessory not supported by this device. Just got my Sprocket 200 yesterday. None of the solutions online are working. Please let me know if you were able to fix your problem.
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I have gone through your Post and would like to help
Please ensure your iPhone has all the latest updates
Next Reset the Sprocket and try connecting again
1. Hold the power button for about 7 seconds total. After 3 seconds, the Status LED light will turn off to indicate the printer is shutting down; continue to hold the Power button until the LED lights start to flash.
2. Release the power button. The LEDs will continue blinking for about 6 seconds.
3. While the LEDs are blinking, press and release the power button. The device will remain off until you power on again.
4. Power on; the printer will be reset to factoring settings. After a factory reset, all settings are reset to factory defaults
Uninstall and Reinstall the HP Sprocket App from the App Store and check for Firmware updates
On your mobile device, open the HP sprocket app.
Tap the Menu icon , and then tap sprocket.
Tap Printer Settings, and then look for a firmware upgrade.
If a firmware upgrade displays, tap Get Firmware Upgrade, and then follow the on-screen prompts to complete the update.
If a firmware upgrade option does not display, the firmware is up-to-date.
Next connect the Sprocket to your iPhone
1. Press and hold the Power Button for 3 seconds to turn on the printer. The Status LED Indicator Light will turn white once fully powered on.
2. Open iPhone® Settings and select Bluetooth. Turn Bluetooth on and then select the printer from the listed devices.
3. Next, launch the sprocket app.
Let me know how it goes
Thank you and have a wonderful day 😊
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