https://devzone.nordicsemi.com/f/nordic-q-a/6641/printing-floating-point-numbers-to-uartHey everyone, I&#39;m trying to print floating point numbers to the UART to debug my application. I know the nrf51 is doing the operations correctly because if I convert the variable to an int I can print it correctly and I get (~)accurate values. Whenen-USTelligent Community 13Sat, 25 Apr 2015 12:19:46 GMThttps://devzone.nordicsemi.com/thread/23283?ContentTypeID=1Sat, 25 Apr 2015 12:19:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d827ddc9-69f0-4cbf-8e01-0e5d9f4aed64maxpaynner<p><a href="http://www.quickmeme.com/img/b1/b1863ec001f174e2d9a3cc0ad89aad0cbf78ddd297256b891bd8ff4662f3f044.jpg">Thanks :) Tested and working!</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23282?ContentTypeID=1Sat, 25 Apr 2015 02:15:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:705c8f3a-9051-424d-8b3d-637d205a8e87Nguyen Hoan Hoang<p>you also need this option <code>-u _printf_float</code></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23281?ContentTypeID=1Fri, 24 Apr 2015 22:07:58 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d3995c16-23e1-467b-88a4-96311a526762maxpaynner<p>Okay, this is in my makefile:</p> <pre><code># use newlib in nano version LDFLAGS += --specs=nano.specs -lc -lnosys </code></pre> <p>And still no floating point support. Any ideas?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23280?ContentTypeID=1Wed, 22 Apr 2015 14:18:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4cd0e2dc-82f3-449b-ac39-549ae93b1401Nguyen Hoan Hoang<p>Follow <a href="http://embeddedsoftdev.blogspot.ca/p/ehal-nrf51.html">this blog</a> for Eclipse based development</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23279?ContentTypeID=1Wed, 22 Apr 2015 14:16:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d4e79607-655d-432a-93d2-fa211e9d8d12maxpaynner<p>I&#39;m using both actually, never figured out how to get eclipse to compile for the nrf51 so I&#39;m using my custom makefile that I call from eclipse using &quot;external tools&quot;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23278?ContentTypeID=1Wed, 22 Apr 2015 13:21:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f6a5cfe8-3d97-4702-bb73-c7ea2145588eNguyen Hoan Hoang<p>Well, it depends on which development environment you use. Each has different way to do it. If you are using makefile with gcc then yes, follow that instruction. If you are using Eclipse project, it is in linker settings...</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23277?ContentTypeID=1Wed, 22 Apr 2015 13:07:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4cbb57a1-67d4-4cdc-a88c-8b0354a8a996maxpaynner<p>Do I just have to follow what&#39;s written here <a href="https://devzone.nordicsemi.com/question/4740/how-to-get-rid-of-impure_data/">devzone.nordicsemi.com/.../</a> to link with newlib-nano?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23276?ContentTypeID=1Wed, 22 Apr 2015 11:07:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:11bdbbb1-14d9-4e39-b527-1c719d820a9aNguyen Hoan Hoang<p>Either link with floating point support. newlib-nano has that option or you do it manually using integer. Cast to int to printf integer part, then take the floating part multiply by 10, 100, 1000 depending on how many digits you want to keep. Don&#39;t forget to add .5 to round up. Then print the int part again. For example 2 decimal points : multiply by 100.0 and printf format is &quot;%d.%02d&quot;, for 4 decimal point : multiply by 10000.0 using format &quot;%d.%04d&quot;.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/23275?ContentTypeID=1Wed, 22 Apr 2015 10:56:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9aa39d02-d448-45eb-a101-e4cd12e392d4Alex<p>You answered your question. Need to compile with Full Printf support. For IAR it is in General Options for example.</p><div style="clear:both;"></div>