diff --git a/tools/atrf-txrx/atrf-txrx.c b/tools/atrf-txrx/atrf-txrx.c
index bedcd92..263d7aa 100644
--- a/tools/atrf-txrx/atrf-txrx.c
+++ b/tools/atrf-txrx/atrf-txrx.c
@@ -63,22 +63,6 @@ enum rx_res {
 };
 
 
-static double tx_pwr_230[] = {
-	 3.0,	 2.6,	 2.1,	 1.6,
-	 1.1,	 0.5,	-0.2,	-1.2,
-	-2.2,	-3.2,	-4.2,	-5.2,
-	-7.2,	-9.2,	-12.2,	-17.2
-};
-
-
-static double tx_pwr_231[] = {
-	 3.0,	 2.8,	 2.3,	 1.8,
-	 1.3,	 0.7,	 0.0,	-1,
-	-2,	-3,	-4,	-5,
-	-7,	-9,	-12,	-17
-};
-
-
 static volatile int run = 1;
 
 
@@ -146,47 +130,6 @@ static void set_rate(struct atrf_dsc *dsc, uint8_t rate)
 }
 
 
-static void set_power(struct atrf_dsc *dsc, double power, int crc)
-{
-	const double *tx_pwr;
-	int n;
-	uint8_t tmp;
-
-	switch (atrf_identify(dsc)) {
-	case artf_at86rf230:
-		tx_pwr = tx_pwr_230;
-		break;
-	case artf_at86rf231:
-		tx_pwr = tx_pwr_231;
-		break;
-	default:
-		abort();
-	}
-
-	for (n = 0; n != sizeof(tx_pwr_230)/sizeof(*tx_pwr_230)-1; n++)
-		if (tx_pwr[n] <= power)
-			break;
-	if (fabs(tx_pwr[n]-power) > 0.01)
-		fprintf(stderr, "TX power %.1f dBm\n", tx_pwr[n]);
-
-	switch (atrf_identify(dsc)) {
-	case artf_at86rf230:
-		atrf_reg_write(dsc, REG_PHY_TX_PWR,
-		    (crc ? TX_AUTO_CRC_ON_230 : 0) | n);
-		break;
-	case artf_at86rf231:
-		tmp = atrf_reg_read(dsc, REG_PHY_TX_PWR);
-		tmp = (tmp & ~TX_PWR_MASK) | n;
-		atrf_reg_write(dsc, REG_PHY_TX_PWR, tmp);
-		atrf_reg_write(dsc, REG_TRX_CTRL_1,
-		    crc ? TX_AUTO_CRC_ON : 0);
-		break;
-	default:
-		abort();
-	}
-}
-
-
 static void receive_message(struct atrf_dsc *dsc)
 {
 	uint8_t buf[MAX_PSDU+1]; /* PSDU+LQI */
@@ -642,15 +585,15 @@ int main(int argc, char *const *argv)
 			receive(dsc, pcap_file);
 			break;
 		case mode_per:
-			set_power(dsc, power, 0);
+			set_power_dBm(dsc, power, 0);
 			transmit_pattern(dsc, pause_s, 0);
 			break;
 		case mode_ping:
-			set_power(dsc, power, 1);
+			set_power_dBm(dsc, power, 1);
 			ping(dsc, pause_s, 0);
 			break;
 		case mode_cont_tx:
-			set_power(dsc, power, 0);
+			set_power_dBm(dsc, power, 0);
 			status = test_mode(dsc, cont_tx, NULL);
 			break;
 		default:
@@ -679,25 +622,25 @@ int main(int argc, char *const *argv)
 		set_rate(dsc, rate);
 		switch (mode) {
 		case mode_msg:
-			set_power(dsc, power, 1);
+			set_power_dBm(dsc, power, 1);
 			transmit(dsc, argv[optind], times);
 			break;
 		case mode_per:
 			times = strtoul(argv[optind+1], &end, 0);
 			if (*end)
 				usage(*argv);
-			set_power(dsc, power, 0);
+			set_power_dBm(dsc, power, 0);
 			transmit_pattern(dsc, pause_s, times);
 			break;
 		case mode_ping:
 			pause_s = strtof(argv[optind], &end);
 			if (*end)
 				usage(*argv);
-			set_power(dsc, power, 1);
+			set_power_dBm(dsc, power, 1);
 			ping(dsc, pause_s, 1);
 			break;
 		case mode_cont_tx:
-			set_power(dsc, power, 0);
+			set_power_dBm(dsc, power, 0);
 			status = test_mode(dsc, cont_tx, argv[optind]);
 			break;
 		default:
diff --git a/tools/include/misctxrx.h b/tools/include/misctxrx.h
index 0bf4305..cf17a77 100644
--- a/tools/include/misctxrx.h
+++ b/tools/include/misctxrx.h
@@ -1,8 +1,8 @@
 /*
  * include/misctxrx.h - Miscellaenous transceiver helper functions
  *
- * Written 2010 by Werner Almesberger
- * Copyright 2010 Werner Almesberger
+ * Written 2010-2011 by Werner Almesberger
+ * Copyright 2010-2011 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -21,4 +21,7 @@
 uint8_t wait_for_interrupt(struct atrf_dsc *dsc, uint8_t wait_for,
     uint8_t ignore, int sleep_us, int timeout);
 
+void set_power_step(struct atrf_dsc *dsc, int power, int crc);
+void set_power_dBm(struct atrf_dsc *dsc, double power, int crc);
+
 #endif /* !MISCTXRX_H */
diff --git a/tools/lib/misctxrx.c b/tools/lib/misctxrx.c
index 9ad5754..5bc7e6e 100644
--- a/tools/lib/misctxrx.c
+++ b/tools/lib/misctxrx.c
@@ -16,12 +16,16 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <signal.h>
+#include <math.h>
 
 #include "at86rf230.h"
 #include "atrf.h"
 #include "misctxrx.h"
 
 
+/* ----- Interrupts -------------------------------------------------------- */
+
+
 static volatile int run = 1;
 
 
@@ -85,3 +89,70 @@ out:
 		raise(SIGINT);
 	return irq;
 }
+
+
+/* ----- Transmit power ---------------------------------------------------- */
+
+
+static double tx_pwr_230[] = {
+	 3.0,	 2.6,	 2.1,	 1.6,
+	 1.1,	 0.5,	-0.2,	-1.2,
+	-2.2,	-3.2,	-4.2,	-5.2,
+	-7.2,	-9.2,	-12.2,	-17.2
+};
+
+
+static double tx_pwr_231[] = {
+	 3.0,	 2.8,	 2.3,	 1.8,
+	 1.3,	 0.7,	 0.0,	-1,
+	-2,	-3,	-4,	-5,
+	-7,	-9,	-12,	-17
+};
+
+
+void set_power_step(struct atrf_dsc *dsc, int power, int crc)
+{
+	uint8_t tmp;
+
+	switch (atrf_identify(dsc)) {
+	case artf_at86rf230:
+		atrf_reg_write(dsc, REG_PHY_TX_PWR,
+		    (crc ? TX_AUTO_CRC_ON_230 : 0) | power);
+		break;
+	case artf_at86rf231:
+		tmp = atrf_reg_read(dsc, REG_PHY_TX_PWR);
+		tmp = (tmp & ~TX_PWR_MASK) | power;
+		atrf_reg_write(dsc, REG_PHY_TX_PWR, tmp);
+		atrf_reg_write(dsc, REG_TRX_CTRL_1,
+		    crc ? TX_AUTO_CRC_ON : 0);
+		break;
+	default:
+		abort();
+	}
+}
+
+
+void set_power_dBm(struct atrf_dsc *dsc, double power, int crc)
+{
+	const double *tx_pwr;
+	int n;
+
+	switch (atrf_identify(dsc)) {
+	case artf_at86rf230:
+		tx_pwr = tx_pwr_230;
+		break;
+	case artf_at86rf231:
+		tx_pwr = tx_pwr_231;
+		break;
+	default:
+		abort();
+	}
+
+	for (n = 0; n != sizeof(tx_pwr_230)/sizeof(*tx_pwr_230)-1; n++)
+		if (tx_pwr[n] <= power)
+			break;
+	if (fabs(tx_pwr[n]-power) > 0.01)
+		fprintf(stderr, "TX power %.1f dBm\n", tx_pwr[n]);
+
+	set_power_step(dsc, n, crc);
+}